高石粉含量人工砂在混凝土中的应用研究

Use of Man-made Sand with High Content Stone Powder in Concrete

通过高石粉含量人工砂的优选、高石粉人工砂混凝土力学性能和干缩性能的试验研究以及与大尺寸原级配混凝土的对比分析,证明了高石粉人工砂用于混凝土工程是可行的,它能提高混凝土力学性能,改善新拌混凝土和易性,提高混凝土抗裂能力.人工砂中石粉的最优含量为16%左右.混凝土干缩随石粉含量增加而增大,但骨料粒径与级配、试件尺寸大小等因素能改变、抑制和减小干缩率;在工程应用中,应加强对高石粉含量人工砂混凝土的早期养护.

Laboratory tests were carried out on the large size concrete specimen (three-graded coarse aggregate) to investigate the mechanical property and dry shrinkage characteristics of the concrete containing high content stone powder man-made sand. The results demonstrate that the high content stone powder man-made sand added in the concrete is helpful to improve the workability, mechanical and anti-cracking property. It is found that the optimum content of the stone powder is 16%, beyond which the dry shrinkage increases with the content of the stone powder. It is noticed that the characteristics of dry shrinkage is also influenced by the size of the specimens, the size and grading of the aggregate etc. The study suggested that the early curing is important for the concrete which uses the high content stone powder man-made sand as its fine aggregate.