Comprehensive Estimation Chemical Prestress and Chemical Press

点击翻译按钮获取中文摘要

Effects of chemical prestress and estimation of expansive energy of expansive concrete are comprehensively discussed on the basis of experiments using uniaxially restrained expansive concrete beams with different fiber reinforced plastics and triaxially restrained cylindrical specimens with piled-up steel rings and steel bars. Both the durableness of expansive energy and the effect of chemical press also are investigated.(1) Aproposed multiaxial restraint testing apparatus consists of piled-up steel rings for the radial restraint and steel bars with end plates for the axial restraint. the testing method is effective in measuring the expansive energy and performing the compressive strength test in order to ascertain the chemical press.(2) The work quantity transferred to steel rings in radial direction was a constant value if the degree of the restraint was changed from 16% to 28%.(3) The ratio of residual expansive energy after two year's triaxial restraint was decreased largely for large the unit content of expansive admixture.(4) The mechanical properties of the expansive concrete depend greatly upon the way of resraining. The triaxial restraint produces a chemical press effect and improves the compressive strength and the Young's modules by 10-30% and 10-20%, respectively. The effect of the degree of restraint on the chemical press is remarkable when the degree of restraint goes to 1%, but the increase in the effect of the chemical press is small if the degree of restraint increases by 5%. The effect of the chemical press became larger as the water-binder ratio became smaller.