泵送混凝土回弹测强曲线试验研究

Experimental study on pressure strength curve of pumping concrete by rebound test

通过兰州地区泵送混凝土抗压强度回弹测强曲线的建立,分析研究了粗骨料、掺合料及外加剂等因素对回弹测强曲线的影响。结果表明:粉煤灰掺合料、破碎卵石等因素对回弹测强曲线影响较大,粉煤灰掺量大于30%时会使得混凝土回弹换算强度高于抗压强度,而破碎卵石的影响则相反,其混凝土回弹换算强度低于抗压强度;由于混凝土原材料及养护条件的不同,兰州地区的泵送混凝土回弹测强曲线比规范推荐的统一曲线的强度推算值略大。

Based on the formed pressure strength curve of the pumping concrete in the area of Lanzhou,the effects of coarse aggregate,admixtures and other additives were analyzed.The results showed that the ratios of broken pebbles and admixture of expanding agents and fly ash had a significant effect on the curve.More specifically,the relative strength of concrete was larger than that of standard sample when the ratio of admixture of expanding agents and fly ash was larger than 30%,while the influence of broken pebbles was adverse,i.e.,the relative pressure strength of concrete with broken pebbles was smaller than that of standard sample.Moreover,due to the differences of raw material and curing condition of concrete,the value of the curve was slightly larger than that recommended in the code.