2014 Volume 70 Issue 4 Pages 356-369
A long-term ASR-expansive HPFRCC was developed. As an application, chemical prestress was introduced into this material by restraining the ASR expansion using reinforcing bars. Uniaxial tension tests were then performed on dumbbell-shaped HPFRCC specimens involving accelerated ASR expansion. The tensile yield strength and tensile ultimate strength were not adversely affected by the expansion. Although the ultimate strain of all specimens was reduced by the expansion, the multiple-cracking properties were observed and the average and standard deviations of crack widths were not affected by the expansion. The length change tests on small size HPFRCC beams reinforced with steel bars showed that the chemical energy conservation law of expansive concrete was valid regarding ASR-expansive HPFRCC. Bending tests on the reinforced HPFRCC beams showed that the cracking strength increased due to chemical prestress induced by ASR. The expansion of chemically prestressed beams was retained even after drying shrinkage. The possibility of controlling ASR expansion by means of LiNO2 impregnation was also ascertained.
