Cement, compressive strength Durability

The compressive strength of AB cements used in dentistry has been widely studied (Wilson McLean, 1988). It is the method, for example, specified in the British Standard on dental cements. However, there is concern that the result is less clinically relevant than the evaluation of flexural strength. Moreover, the latter is more discriminating (Prosser et al., 1984). Despite this, compressive strength has been used to indicate clinical acceptability phosphate-bonded cements with low compressive strength tend to be unsatisfactory in other respects such as durability, and... 

Series Mix Air- entraining agent Water-reducing admixture Cement content (kg m - ) Water- cement ratio 28-day compressive strength (N mm-2) Air content (%) Slump (mm) Durability factor ASTM C290 1967... 

Physical properties of CSA-contaming concretes (compressive strength, creep, modulus of elasticity and durability) are comparable to those of corresponding Portland cement concretes, especially when CSA is used at dosages of 8-11%. When the dosage exceeds the ranges mentioned above and no restraint is provided either internally (by reinforcement) or... 

Damp-proofing admixtures include soaps and fatty acids which react with the cement hydrates to modify workability, bleeding and settlement, air content, compressive strength and durability characteristics. Mix proportions, mix consistency, admixture dosage and poor mixing influence the effects produced by the admixture. In cement-rich mixes void content is often increased, resulting in increased permeability. Since the admixture... 

FGD scrubber material Stabilized base - Stabilized or fixated FGD scrubber material has been used successfully for road base construction, at a number of different sites in Florida, Pennsylvania, Ohio, and Texas - Stabilization or fixation of FGD scrubber material can be accomphshed by the addition of quicklime and pozzolanic fly ash, Portland cement, or selfcementing fly ash - The FGD scrubber sludge is dewatered before the addition of stabilization or fixation reagents - Additional fixation reagents may need to be added for stabilized base construction in order to meet compressive strength or durability requirements 66-80... 

The largest improvement in structural and durability properties has been obtained with the PIC system. With the impregnation of a macromolecular compound, the compressive strength can be increased four times or more, the modulus of elasticity increased at least two times, the water and salt permeability reduced by 99%, the freeze-thaw resistance improved enormously, and—in contrast to conventional concrete—PIC exhibits essentially zero creep properties. Both strength and durability are strongly dependent on the fraction of the porosity of the cement phase that is filled with polymer. 

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