Mortar Constituent of Concrete in Compression

Abstract

A study of the behavior of the mortar constituent of concrete under monotonic and cyclic uniaxial compression is summarized. Two mixes were used, with proportions corresponding to concretes with water-cement ratios of 0.5 and 0.6. Forty-four groups of three specimens each were tested at ages ranging from 5 to 70 days. Complete monotonic and cyclic envelopes were obtained using six different loading regimes, including cycles to specified strains. Major emphasis was placed on tests using relatively high stress cycles. Accumulation of residual strain and changes in the initial modulus of elasticity were used to evaluate damage and structural change. The maximum strain appears to be the major factor con trolling damage in mortar, but the total cyclic strain range and/or the number of load cycles also play significant roles. The behavior of concrete and mortar is highly similar, indicating that the mortar constituent may control the primary stress-strain behavior of concrete.