Comprehensive Estimation Chemical Prestress and Chemical Press

通过不同纤维增强塑料的单轴约束膨胀混凝土梁和钢环钢筋堆砌的三轴约束柱试件试验，全面讨论了化学预应力对膨胀混凝土膨胀能的影响和估算。研究了膨胀能的耐久性和化学压力的影响。(1)提出了一种多轴约束试验装置，该装置由径向约束钢环堆积和轴向约束带端板的钢筋组成。该试验方法在测定膨胀能和进行抗压强度试验以确定化学压力方面是有效的。(2)当约束程度从16%变化到28%时，传递给钢环的径向功为恒定值。(3)膨胀掺量越大，三轴约束2年后的残余膨胀能比显著降低。(4)膨胀混凝土的力学性能在很大程度上取决于约束方式。三轴约束产生化学压力效应，可将抗压强度和杨氏模量分别提高10-30%和10-20%。当约束度达到1%时，约束度对化学压机的影响是显著的，但当约束度增加5%时，化学压机的效果增加很小。水胶比越小，化学压力的影响越大。

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.