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	<id>https://damtoolbox.org/index.php?action=history&amp;feed=atom&amp;title=Precast_Concrete_Blocks</id>
	<title>Precast Concrete Blocks - Revision history</title>
	<link rel="self" type="application/atom+xml" href="https://damtoolbox.org/index.php?action=history&amp;feed=atom&amp;title=Precast_Concrete_Blocks"/>
	<link rel="alternate" type="text/html" href="https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;action=history"/>
	<updated>2026-04-11T19:26:28Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.40.0</generator>
	<entry>
		<id>https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=7144&amp;oldid=prev</id>
		<title>Mpollei@gfnet.com at 19:42, 11 July 2023</title>
		<link rel="alternate" type="text/html" href="https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=7144&amp;oldid=prev"/>
		<updated>2023-07-11T19:42:46Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 19:42, 11 July 2023&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l24&quot;&gt;Line 24:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 24:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;noautolinks&amp;gt;==Best Practices Resources==&amp;lt;/noautolinks&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;noautolinks&amp;gt;==Best Practices Resources==&amp;lt;/noautolinks&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Document Icon}} [[Technical Manual: Overtopping Protection for Dams (FEMA P-1015) | Technical Manual: Overtopping Protection for Dams (FEMA P-1015), FEMA&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;, 2014&lt;/del&gt;]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Document Icon}} [[Technical Manual: Overtopping Protection for Dams (FEMA P-1015) | Technical Manual: Overtopping Protection for Dams (FEMA P-1015), FEMA]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Trainings==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Trainings==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Mpollei@gfnet.com</name></author>
	</entry>
	<entry>
		<id>https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=5532&amp;oldid=prev</id>
		<title>Rmanwaring at 00:19, 14 December 2022</title>
		<link rel="alternate" type="text/html" href="https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=5532&amp;oldid=prev"/>
		<updated>2022-12-14T00:19:09Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 00:19, 14 December 2022&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l15&quot;&gt;Line 15:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 15:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;*&amp;#039;&amp;#039;&amp;#039; &amp;#039;&amp;#039;Butt-jointed:&amp;#039;&amp;#039; &amp;#039;&amp;#039;&amp;#039;Commercially-available concrete [[construction]] blocks, also known as concrete masonry units (CMUs) or cinder blocks, that are normally used in the construction of walls for buildings. These have a large open area and are hand-placed with butt joints on the earth surface for erosion control. This system would only be applied to very low head installations due to failure under fairly low velocities not considered comparable for most overtopping situations.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;*&amp;#039;&amp;#039;&amp;#039; &amp;#039;&amp;#039;Butt-jointed:&amp;#039;&amp;#039; &amp;#039;&amp;#039;&amp;#039;Commercially-available concrete [[construction]] blocks, also known as concrete masonry units (CMUs) or cinder blocks, that are normally used in the construction of walls for buildings. These have a large open area and are hand-placed with butt joints on the earth surface for erosion control. This system would only be applied to very low head installations due to failure under fairly low velocities not considered comparable for most overtopping situations.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&quot;All types, except &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;AB &lt;/del&gt;mats (fabric-formed concrete), are manufactured at a precast concrete facility using a high-volume steel mold that is shipped close to the project under construction for standard applications. Some may use a plastic form or mold to cast the blocks if a unique situation develops. Most ACBs are from&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&quot;All types, except &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;ACB &lt;/ins&gt;mats (fabric-formed concrete), are manufactured at a precast concrete facility using a high-volume steel mold that is shipped close to the project under construction for standard applications. Some may use a plastic form or mold to cast the blocks if a unique situation develops. Most ACBs are from&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;4 to 9 inches in thickness. Each product may or may not have an open area equal to anywhere from 2.5 percent for the wedge-shaped blocks, to 18-35 percent for other types of articulating concrete blocks. Some varieties of blocks rely on a [[Vegetative Cover|vegetative cover]] grown in soil placed into open areas of the blocks or over the top of the blocks to improve performance.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;4 to 9 inches in thickness. Each product may or may not have an open area equal to anywhere from 2.5 percent for the wedge-shaped blocks, to 18-35 percent for other types of articulating concrete blocks. Some varieties of blocks rely on a [[Vegetative Cover|vegetative cover]] grown in soil placed into open areas of the blocks or over the top of the blocks to improve performance.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Rmanwaring</name></author>
	</entry>
	<entry>
		<id>https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=5531&amp;oldid=prev</id>
		<title>Rmanwaring at 00:17, 14 December 2022</title>
		<link rel="alternate" type="text/html" href="https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=5531&amp;oldid=prev"/>
		<updated>2022-12-14T00:17:06Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 00:17, 14 December 2022&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l4&quot;&gt;Line 4:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 4:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;!-- Introductory paragraph or topic page summary --&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;!-- Introductory paragraph or topic page summary --&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;Precast concrete blocks can be used over earth materials to provide a hard surface for flow to pass safely without eroding the underlying surface, and are commonly referred to as articulating concrete blocks (ACB) when used for this purpose. An ACB system is comprised of a matrix of individual concrete blocks placed together to form an erosion-resistant revetment with specific hydraulic performance characteristics. The term “articulating” implies the ability of the&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;Precast concrete blocks can be used over earth materials to provide a hard surface for flow to pass safely without eroding the underlying surface, and are commonly referred to as articulating concrete blocks (ACB) when used for this purpose. An ACB system is comprised of a matrix of individual concrete blocks placed together to form an erosion-resistant revetment with specific hydraulic performance characteristics. The term “articulating” implies the ability of the&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;matrix to conform to minor changes in the subgrade while remaining interconnected with geometric interlock and/or additional system components such as cables or anchors. These systems have also been referred to as cellular concrete mats (CCM).&quot; &amp;lt;ref name=&quot;FEMA1015&quot;&amp;gt;[[Technical Manual: Overtopping Protection for Dams (FEMA P-1015)| Technical Manual: Overtopping Protection for Dams (FEMA P-1015), FEMA, 2014]]&amp;lt;/ref&amp;gt;  &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;matrix to conform to minor changes in the subgrade while remaining interconnected with geometric interlock and/or additional system components such as cables or anchors. These systems have also been referred to as cellular concrete mats (CCM).&quot; &amp;lt;ref name=&quot;FEMA1015&quot;&amp;gt;[[Technical Manual: Overtopping Protection for Dams (FEMA P-1015) | Technical Manual: Overtopping Protection for Dams (FEMA P-1015), FEMA, 2014]]&amp;lt;/ref&amp;gt;  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&quot;There are many types of precast concrete blocks, each with its own geometry, useful application based upon hydraulic performance and erosion prevention, installation procedures, aesthetic value, and cost. Of most importance for providing [[Overtopping Protection|overtopping protection]] is to select a product that has been tested under the flow conditions expected during overtopping. Applications for overtopping protection typically include high velocity flows, steep slopes, and possibly [[Energy Dissipation|energy dissipation]] on the flow surface.&quot;&amp;lt;ref name=&quot;FEMA1015&quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&quot;There are many types of precast concrete blocks, each with its own geometry, useful application based upon hydraulic performance and erosion prevention, installation procedures, aesthetic value, and cost. Of most importance for providing [[Overtopping Protection|overtopping protection]] is to select a product that has been tested under the flow conditions expected during overtopping. Applications for &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Overtopping Protection|&lt;/ins&gt;overtopping protection&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/ins&gt;typically include high velocity flows, steep slopes, and possibly [[Energy Dissipation|energy dissipation]] on the flow surface.&quot;&amp;lt;ref name=&quot;FEMA1015&quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;The four main types of articulating concrete blocks are described below.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;The four main types of articulating concrete blocks are described below.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l22&quot;&gt;Line 22:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 22:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Examples==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Examples==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Website Icon}} [[Riprap and Concrete Blocks Examples|See examples of riprap and concrete block armoring]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Website Icon}} [[Riprap and Concrete Blocks Examples|See examples of riprap and concrete block armoring]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;lt;noautolinks&gt;==Best Practices Resources==&amp;lt;/noautolinks&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;{{Document Icon}} [[Technical Manual: Overtopping Protection for Dams (FEMA P-1015) | Technical Manual: Overtopping Protection for Dams (FEMA P-1015), FEMA, 2014]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Trainings==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Trainings==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Rmanwaring</name></author>
	</entry>
	<entry>
		<id>https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=5530&amp;oldid=prev</id>
		<title>Rmanwaring at 00:16, 14 December 2022</title>
		<link rel="alternate" type="text/html" href="https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=5530&amp;oldid=prev"/>
		<updated>2022-12-14T00:16:27Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 00:16, 14 December 2022&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l4&quot;&gt;Line 4:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 4:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;!-- Introductory paragraph or topic page summary --&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;!-- Introductory paragraph or topic page summary --&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;Precast concrete blocks can be used over earth materials to provide a hard surface for flow to pass safely without eroding the underlying surface, and are commonly referred to as articulating concrete blocks (ACB) when used for this purpose. An ACB system is comprised of a matrix of individual concrete blocks placed together to form an erosion-resistant revetment with specific hydraulic performance characteristics. The term “articulating” implies the ability of the&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;Precast concrete blocks can be used over earth materials to provide a hard surface for flow to pass safely without eroding the underlying surface, and are commonly referred to as articulating concrete blocks (ACB) when used for this purpose. An ACB system is comprised of a matrix of individual concrete blocks placed together to form an erosion-resistant revetment with specific hydraulic performance characteristics. The term “articulating” implies the ability of the&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;matrix to conform to minor changes in the subgrade while remaining interconnected with geometric interlock and/or additional system components such as cables or anchors. These systems have also been referred to as cellular concrete mats (CCM).&quot; &amp;lt;ref name=&quot;FEMA1015&quot;&amp;gt;[[Technical Manual: Overtopping Protection for Dams (FEMA P-1015)| Technical Manual: Overtopping Protection for Dams (FEMA P-1015) &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;(Federal Emergency Management Agency&lt;/del&gt;, 2014&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;)&lt;/del&gt;]]&amp;lt;/ref&amp;gt;  &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;matrix to conform to minor changes in the subgrade while remaining interconnected with geometric interlock and/or additional system components such as cables or anchors. These systems have also been referred to as cellular concrete mats (CCM).&quot; &amp;lt;ref name=&quot;FEMA1015&quot;&amp;gt;[[Technical Manual: Overtopping Protection for Dams (FEMA P-1015)| Technical Manual: Overtopping Protection for Dams (FEMA P-1015)&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;, FEMA&lt;/ins&gt;, 2014]]&amp;lt;/ref&amp;gt;  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&quot;There are many types of precast concrete blocks, each with its own geometry, useful application based upon hydraulic performance and erosion prevention, installation procedures, aesthetic value, and cost. Of most importance for providing overtopping protection is to select a product that has been tested under the flow conditions expected during overtopping. Applications for overtopping protection typically include high velocity flows, steep slopes, and possibly energy dissipation on the flow surface.&quot;&amp;lt;ref name=&quot;FEMA1015&quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&quot;There are many types of precast concrete blocks, each with its own geometry, useful application based upon hydraulic performance and erosion prevention, installation procedures, aesthetic value, and cost. Of most importance for providing &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Overtopping Protection|&lt;/ins&gt;overtopping protection&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/ins&gt;is to select a product that has been tested under the flow conditions expected during overtopping. Applications for overtopping protection typically include high velocity flows, steep slopes, and possibly &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Energy Dissipation|&lt;/ins&gt;energy dissipation&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/ins&gt;on the flow surface.&quot;&amp;lt;ref name=&quot;FEMA1015&quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;The four main types of articulating concrete blocks are described below.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;The four main types of articulating concrete blocks are described below.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l16&quot;&gt;Line 16:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 16:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;All types, except AB mats (fabric-formed concrete), are manufactured at a precast concrete facility using a high-volume steel mold that is shipped close to the project under construction for standard applications. Some may use a plastic form or mold to cast the blocks if a unique situation develops. Most ACBs are from&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;All types, except AB mats (fabric-formed concrete), are manufactured at a precast concrete facility using a high-volume steel mold that is shipped close to the project under construction for standard applications. Some may use a plastic form or mold to cast the blocks if a unique situation develops. Most ACBs are from&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;4 to 9 inches in thickness. Each product may or may not have an open area equal to anywhere from 2.5 percent for the wedge-shaped blocks, to 18-35 percent for other types of articulating concrete blocks. Some varieties of blocks rely on a vegetative cover grown in soil placed into open areas of the blocks or over the top of the blocks to improve performance.&quot;&amp;lt;ref name=&quot;FEMA1015&quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;4 to 9 inches in thickness. Each product may or may not have an open area equal to anywhere from 2.5 percent for the wedge-shaped blocks, to 18-35 percent for other types of articulating concrete blocks. Some varieties of blocks rely on a &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Vegetative Cover|&lt;/ins&gt;vegetative cover&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/ins&gt;grown in soil placed into open areas of the blocks or over the top of the blocks to improve performance.&quot;&amp;lt;ref name=&quot;FEMA1015&quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br/&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;All products require placement over a smooth subgrade with a geotextile and/or a bedding or drainage layer between the subgrade and the block system. Installation requirements and techniques vary with the product and affect product performance. Product performance in overtopping or high velocity flow conditions down steep slopes varies significantly. Only products that have been tested in like conditions of the design application with flume or field test conditions should be considered for use.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;quot;All products require placement over a smooth subgrade with a geotextile and/or a bedding or drainage layer between the subgrade and the block system. Installation requirements and techniques vary with the product and affect product performance. Product performance in overtopping or high velocity flow conditions down steep slopes varies significantly. Only products that have been tested in like conditions of the design application with flume or field test conditions should be considered for use.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Rmanwaring</name></author>
	</entry>
	<entry>
		<id>https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=4821&amp;oldid=prev</id>
		<title>Grichards: Created page with &quot;__NOTOC__ Category:Overtopping Protection ---- &lt;!-- Introductory paragraph or topic page summary --&gt; &quot;Precast concrete blocks can be used over earth materials to provide a hard surface for flow to pass safely without eroding the underlying surface, and are commonly referred to as articulating concrete blocks (ACB) when used for this purpose. An ACB system is comprised of a matrix of individual concrete blocks placed together to form an erosion-resistant revetment wit...&quot;</title>
		<link rel="alternate" type="text/html" href="https://damtoolbox.org/index.php?title=Precast_Concrete_Blocks&amp;diff=4821&amp;oldid=prev"/>
		<updated>2022-12-02T20:35:07Z</updated>

		<summary type="html">&lt;p&gt;Created page with &amp;quot;__NOTOC__ &lt;a href=&quot;/index.php?title=Category:Overtopping_Protection&amp;amp;action=edit&amp;amp;redlink=1&quot; class=&quot;new&quot; title=&quot;Category:Overtopping Protection (page does not exist)&quot;&gt;Category:Overtopping Protection&lt;/a&gt; ---- &amp;lt;!-- Introductory paragraph or topic page summary --&amp;gt; &amp;quot;Precast concrete blocks can be used over earth materials to provide a hard surface for flow to pass safely without eroding the underlying surface, and are commonly referred to as articulating concrete blocks (ACB) when used for this purpose. An ACB system is comprised of a matrix of individual concrete blocks placed together to form an erosion-resistant revetment wit...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;__NOTOC__&lt;br /&gt;
[[Category:Overtopping Protection]]&lt;br /&gt;
----&lt;br /&gt;
&amp;lt;!-- Introductory paragraph or topic page summary --&amp;gt;&lt;br /&gt;
&amp;quot;Precast concrete blocks can be used over earth materials to provide a hard surface for flow to pass safely without eroding the underlying surface, and are commonly referred to as articulating concrete blocks (ACB) when used for this purpose. An ACB system is comprised of a matrix of individual concrete blocks placed together to form an erosion-resistant revetment with specific hydraulic performance characteristics. The term “articulating” implies the ability of the&lt;br /&gt;
matrix to conform to minor changes in the subgrade while remaining interconnected with geometric interlock and/or additional system components such as cables or anchors. These systems have also been referred to as cellular concrete mats (CCM).&amp;quot; &amp;lt;ref name=&amp;quot;FEMA1015&amp;quot;&amp;gt;[[Technical Manual: Overtopping Protection for Dams (FEMA P-1015)| Technical Manual: Overtopping Protection for Dams (FEMA P-1015) (Federal Emergency Management Agency, 2014)]]&amp;lt;/ref&amp;gt; &lt;br /&gt;
&lt;br /&gt;
&amp;quot;There are many types of precast concrete blocks, each with its own geometry, useful application based upon hydraulic performance and erosion prevention, installation procedures, aesthetic value, and cost. Of most importance for providing overtopping protection is to select a product that has been tested under the flow conditions expected during overtopping. Applications for overtopping protection typically include high velocity flows, steep slopes, and possibly energy dissipation on the flow surface.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;The four main types of articulating concrete blocks are described below.&lt;br /&gt;
*&amp;#039;&amp;#039;&amp;#039; &amp;#039;&amp;#039;Cable-tied:&amp;#039;&amp;#039; &amp;#039;&amp;#039;&amp;#039;Concrete block units that are individually formed with or without open areas, and laced together with cables into large, sometimes uniquely-shaped mattresses for installation. The blocks are normally cabled together (both longitudinally and laterally) at the manufacturing plant and are delivered to the site on flat-bed trucks for placement as a mattress with a crane. &lt;br /&gt;
*&amp;#039;&amp;#039;&amp;#039; &amp;#039;&amp;#039;Articulating Block (AB):&amp;#039;&amp;#039; &amp;#039;&amp;#039;&amp;#039;Fabric-formed, cable-reinforced, concrete mattresses that are cast in place. The AB fabric form consists of a series of compartments linked by an interwoven perimeter. Grout ducts interconnect the compartments, and high-strength revetment cables are installed between and through the compartments and grout ducts. Once filled with grout or small aggregate concrete, the AB mats become a mattress of pillow-shaped, rectangular concrete blocks. The interwoven perimeters between the blocks serve as hinges to permit articulation. The cables remain embedded in the concrete blocks to link the blocks together.&lt;br /&gt;
*&amp;#039;&amp;#039;&amp;#039; &amp;#039;&amp;#039;Interlocking:&amp;#039;&amp;#039; &amp;#039;&amp;#039;&amp;#039;Concrete block units that are individually formed with mortise and tenon-type features that are fit together on site. Some interlocking blocks have open areas, and some are solid. Some may also use cables, but this type is generally hand-placed or brought to the site on geotextile mats.&lt;br /&gt;
*&amp;#039;&amp;#039;&amp;#039; &amp;#039;&amp;#039;Overlapping:&amp;#039;&amp;#039; &amp;#039;&amp;#039;&amp;#039;Concrete block units that are tapered wedge-shaped blocks or concrete slabs that are overlapped shingle-fashion from the toe of the slope to the crest. The block units are formed at the manufacturing plant and delivered to the site on pallets. Individual units in the system are staggered and interlocked for enhanced [[stability]]. Each row of units is laterally offset by one-half of a block width from the adjacent row. When placed, the blocks form a stepped surface with slots providing open areas for venting subgrade uplift pressures. They are hand-placed, but have been cabled together on site.&lt;br /&gt;
*&amp;#039;&amp;#039;&amp;#039; &amp;#039;&amp;#039;Butt-jointed:&amp;#039;&amp;#039; &amp;#039;&amp;#039;&amp;#039;Commercially-available concrete [[construction]] blocks, also known as concrete masonry units (CMUs) or cinder blocks, that are normally used in the construction of walls for buildings. These have a large open area and are hand-placed with butt joints on the earth surface for erosion control. This system would only be applied to very low head installations due to failure under fairly low velocities not considered comparable for most overtopping situations.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;All types, except AB mats (fabric-formed concrete), are manufactured at a precast concrete facility using a high-volume steel mold that is shipped close to the project under construction for standard applications. Some may use a plastic form or mold to cast the blocks if a unique situation develops. Most ACBs are from&lt;br /&gt;
4 to 9 inches in thickness. Each product may or may not have an open area equal to anywhere from 2.5 percent for the wedge-shaped blocks, to 18-35 percent for other types of articulating concrete blocks. Some varieties of blocks rely on a vegetative cover grown in soil placed into open areas of the blocks or over the top of the blocks to improve performance.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;All products require placement over a smooth subgrade with a geotextile and/or a bedding or drainage layer between the subgrade and the block system. Installation requirements and techniques vary with the product and affect product performance. Product performance in overtopping or high velocity flow conditions down steep slopes varies significantly. Only products that have been tested in like conditions of the design application with flume or field test conditions should be considered for use.&amp;quot;&amp;lt;ref name=&amp;quot;FEMA1015&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Examples==&lt;br /&gt;
{{Website Icon}} [[Riprap and Concrete Blocks Examples|See examples of riprap and concrete block armoring]]&lt;br /&gt;
&lt;br /&gt;
==Trainings==&lt;br /&gt;
{{Video Icon}} [[On-Demand Webinar: Introduction to Armoring Embankment Dams and Earth-Cut Spillways with ACBs]]&lt;br /&gt;
&lt;br /&gt;
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{{Citations}}&lt;br /&gt;
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{{revhistinf}}&lt;/div&gt;</summary>
		<author><name>Grichards</name></author>
	</entry>
</feed>