Preparation and properties of non-autoclaved high-strength pile concrete with anhydrite and ground granulated blast-furnace slag

Abstract

The promotion of non-autoclaved production technology is vital to realize long-term sustainable development of pipe pile industry. By optimizing the mix proportion and curing condition, non-autoclaved high-strength pile concrete can be produced, thereby facilitating the pipe pile industry. This study was undertaken to prepare high-strength concrete with anhydrite and ground granulated blast-furnace slag (GGBS). The effects of anhydrite, GGBS and steam curing on workability of cement paste as well as compressive strength, hydration process and microstructure of concrete were investigated. Experimental results showed that the addition of anhydrite and GGBS increased the initial flowability and affected the setting time of cement paste. Steam curing promoted the formation of ettringite and significantly improved the early strength of concrete. Anhydrite and GGBS incorporation brought SO42- and amorphous phase into hydration reaction, which was further accelerated by steam curing. For the steam-curing concrete with 5 % anhydrite and 20∼30 % GGBS, compressive strength was more than 108 MPa at 90 days. This study provided a guide for the production of non-autoclaved high-strength pile concrete with anhydrite and GGBS in pipe pile industry.

Keywords

• Non-autoclaved pipe pile
• High-strength concrete
• Anhydrite
• Slag
• Compressive strength