Mortars Volume change

Potential volume change of cement—aggregate combinations Accelerated detection of potentially deleterious expansion of mortar bars due to alkali-silica reaction... 

There is some controversy as to whether high-lime mortar is preferable to portland cement mortar for tuck pointing. High-lime mortar is suggested for use on old bnildings because it is soft and porous, has low volume change, and is slightly soluble in water. 

Sample Preparation Prepare an enzyme solution so that 1 mL of the final dilution will produce a relative fluidity change between 0.18 and 0.22 in 5 min under the conditions of the assay. Weigh the enzyme, and quantitatively transfer it to a glass mortar. Triturate with water and quantitatively transfer the mixture to an appropriate volumetric flask. Dilute to volume with water, and filter the enzyme solution through Whatman No. 1 filter paper before use. 

Some of the tar sands were extracted exhaustively with benzene-ethanol (3 1.) in a Soxhlet extractor to yield organic materials, and only those materials so obtained will be subsequently referred to as bitumens. This process does not remove all organic materials from some tar sands, and so another method of extraction was used. In the alternate procedure, tar sands first were pulverized in a mortar and pestle. Tnen the sample was transferred to Erlenmeyer fiasks and treated with successive volumes of n-heptane until less than 25 mg of material was dissolved. Each volume of heptane solution was filtered on a sintered glass funnel (coarse porosity), and the heptane then was removed. After heptane was observed to dissolve little material, the solvent was changed to benzene and after this to a mixture of benzene-methanol (1 1). Finally, the sands were extracted with several portions of warm pyridine. 

It is noteworthy that samples SB4 and SB5 as well as KVl and SNl although seemingly identical in terms of component minerals and composition (Table I), vary considerably in terms of ranges of intrusion pore radii and volumes. A probable factor controlling pore size in these mortars is the change in the water content of CaSO IH2O when the latter is made into a paste. 

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