免压蒸高性能混凝土管桩掺合料的试验研究

Study on non-steam autoclaved PHC admixture in the concrete

研制开发一种新型的免压蒸PH C管桩掺合料,其主要成分是粉煤灰、矿渣和极少量的激发剂。以30%替代水泥,能省去压蒸养护过程,仅在蒸养条件下就能达到管桩出厂强度。研究结果表明,采用免压蒸PH C管桩掺合料有更好的和易性,在掺量为30%～35%时,蒸养14h,抗压强度达到86.5M Pa,劈裂抗拉强度达到4.4M Pa,略低于掺磨细砂粉经蒸养和压蒸养护的PH C管桩混凝土,而两者抗渗性相当。掺有免压蒸PH C管桩掺合料制备的PH C管桩,能满足管桩产品的抗弯性能要求,抗弯强度达到A级水平。

A new type admixture for PHC pile without steam-autoclaved curing is resarched and developed. Non-steam autoclaved PHC pile admixture mainly contains fly ash, granulated blast furnace and little high- activity activator. When the content of the admixture is 30% （mass fraction） in cement,the pile strength can be satisfied in the steam curing condition and steam-autoclaved process can be elided. The result shows that the PHC concrete has better workability when use our additive. In the case of the admixture dosage from 30% to 35% ,the PHC concrete is kept for 14h in the steam curing,the concrete compressive strength and splitting strength can achieve 88.5MPa and 4.4MPa respectively. The result is lower than the concrete with ground quartzite powder which must be taken in both steam curing and steam-autoclaved curing. But the penetrability is nearly equal. The two kind of pile quality is both eligible and the main flexural performance can add up to grade A.