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	<id>http://marspedia.org/index.php?action=history&amp;feed=atom&amp;title=Portland_Cement</id>
	<title>Portland Cement - Revision history</title>
	<link rel="self" type="application/atom+xml" href="http://marspedia.org/index.php?action=history&amp;feed=atom&amp;title=Portland_Cement"/>
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	<updated>2026-08-27T11:36:47Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
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	<entry>
		<id>http://marspedia.org/index.php?title=Portland_Cement&amp;diff=143049&amp;oldid=prev</id>
		<title>RichardWSmith: fixing link.</title>
		<link rel="alternate" type="text/html" href="http://marspedia.org/index.php?title=Portland_Cement&amp;diff=143049&amp;oldid=prev"/>
		<updated>2026-08-20T00:53:32Z</updated>

		<summary type="html">&lt;p&gt;fixing link.&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 01:53, 20 August 2026&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-l7&quot;&gt;Line 7:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 7:&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;Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, (3 CaO·SiO2, and 2 CaO·SiO2), the remainder consisting of aluminium- and iron-containing clinker phases and other compounds. The ratio of CaO to SiO2 shall not be less than 2.0. The magnesium oxide content (MgO) shall not exceed 5.0% by mass.&amp;quot;&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;Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, (3 CaO·SiO2, and 2 CaO·SiO2), the remainder consisting of aluminium- and iron-containing clinker phases and other compounds. The ratio of CaO to SiO2 shall not be less than 2.0. The magnesium oxide content (MgO) shall not exceed 5.0% by mass.&amp;quot;&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;Limestone is a mineral created by life on Earth, and is unlikely to be found in any large amounts on Mars.  Since 2/3 of the mass of Portland cement is limestone this will make it more expensive than on Earth.  However, Calcium Carbonate (CaCO3) has been found formed by non-biological processes at 3 to 5% concentrations in polar soils by the Mars [[Phoenix Lander]], so we may be able to find local deposits.  &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;Limestone is a mineral created by life on Earth, and is unlikely to be found in any large amounts on Mars.  Since 2/3 of the mass of Portland cement is limestone this will make it more expensive than on Earth.  However, Calcium Carbonate (CaCO3) has been found formed by non-biological processes at 3 to 5% concentrations in polar soils by the Mars [[&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Phoenix Mars Mission | &lt;/ins&gt;Phoenix Lander]], so we may be able to find local deposits.  &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;[[Sorel Cement]] will likely be cheaper on Mars, as well as being stronger.  However, it erodes when exposed to water.&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;[[Sorel Cement]] will likely be cheaper on Mars, as well as being stronger.  However, it erodes when exposed to water.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

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		<author><name>RichardWSmith</name></author>
	</entry>
	<entry>
		<id>http://marspedia.org/index.php?title=Portland_Cement&amp;diff=143048&amp;oldid=prev</id>
		<title>RichardWSmith: Creating Portland cement page.</title>
		<link rel="alternate" type="text/html" href="http://marspedia.org/index.php?title=Portland_Cement&amp;diff=143048&amp;oldid=prev"/>
		<updated>2026-08-20T00:52:31Z</updated>

		<summary type="html">&lt;p&gt;Creating Portland cement page.&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;Portland cement is the most common type of cement on Earth.  When mixed with sand, gravel and water it forms concrete.&lt;br /&gt;
&lt;br /&gt;
It is made by heating limestone (CaCO3) and clay minerals in a kiln to form clinker (small pebble like accretions) which are then ground into a powder.&lt;br /&gt;
&lt;br /&gt;
The European standard for Portland cement is:&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, (3 CaO·SiO2, and 2 CaO·SiO2), the remainder consisting of aluminium- and iron-containing clinker phases and other compounds. The ratio of CaO to SiO2 shall not be less than 2.0. The magnesium oxide content (MgO) shall not exceed 5.0% by mass.&amp;quot;&lt;br /&gt;
&lt;br /&gt;
Limestone is a mineral created by life on Earth, and is unlikely to be found in any large amounts on Mars.  Since 2/3 of the mass of Portland cement is limestone this will make it more expensive than on Earth.  However, Calcium Carbonate (CaCO3) has been found formed by non-biological processes at 3 to 5% concentrations in polar soils by the Mars [[Phoenix Lander]], so we may be able to find local deposits. &lt;br /&gt;
&lt;br /&gt;
[[Sorel Cement]] will likely be cheaper on Mars, as well as being stronger.  However, it erodes when exposed to water.&lt;/div&gt;</summary>
		<author><name>RichardWSmith</name></author>
	</entry>
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