Toughening method of ultrahigh-performance concrete

Abstract

The invention discloses a toughening method of ultrahigh-performance concrete. According to the invention, carbon nanotubes, cellulose and zinc phosphate surface-modified steel fibers are added into raw materials of the ultrahigh-performance concrete and are uniformly mixed to obtain a mixture, and the mixture is poured along the main stress direction of a component, so fiber orientation in the ultrahigh-performance concrete component tends to the main stress direction. The carbon nanotubes and the cellulose are added, so higher tensile strength and toughness are obtained compared with concrete obtained by independently adding the carbon nanotubes or the cellulose; and a better toughening effect is obtained by adopting two fiber toughening technologies, namely steel fiber orientation and steel fiber surface modification, compared with concrete obtained by independently using one fiber toughening technology. By integrating four measures, the cracking strength of the ultrahigh-performance concrete is improved by 77.4%, the tensile strength of the ultrahigh-performance concrete is improved by 129.5%, and the peak deflection of the ultrahigh-performance concrete is improved by 113.6%,so it is indicated that the scheme obviously enhances the cracking resistance and tensile toughness of the ultrahigh-performance concrete.

Description

technical field [0001] The invention belongs to the field of ultra-high-performance concrete, and in particular relates to a toughening method for ultra-high-performance concrete. Background technique [0002] Since the compressive strength of ultra-high-performance concrete (UHPC) exceeds 150MPa, ultra-high-performance concrete is expected to become a substitute for ordinary concrete and make concrete structures develop by leaps and bounds. However, the tensile strength of ultra-high-performance concrete is only 10-20MPa, and the cracking strength does not exceed 10MPa. Therefore, ultra-high-performance concrete cannot bear large tensile stress. In engineering applications, thinner ultra-high-performance concrete structures and steel The structure can achieve very excellent toughness and crack resistance, but when the thickness of the ultra-high performance concrete structure is large, the limitations of ultra-high performance concrete in terms of tensile and crack resistan...

AI Technical Summary

Problems solved by technology

However, the tensile strength of ultra-high-performance concrete is only 10-20MPa, and the cracking strength does not exceed 10MPa. Therefore, ultra-high-performance concrete cannot bear large tensile stress. In engineering applications, thinner ultra-high-performance concrete structures and steel The structure can achieve very excellent toughness and crack resistance, but when the thickness of the ultra-high performance concrete structure is large, the limitations of ultra-high performance concrete in terms of tensile and crack resistance will limit its application

Images