笔者从事混凝土质量控制具体操作的时候,主要使用P.O32.5水泥,水泥用量比P.O42.5水泥高。商品混凝土的市场规模还没有现在大,掺合料的供应没有现在那么紧张,粉煤灰的质量较好,掺量较高。那时候的材料成本低,混凝土售价较高,竞争没有现在激烈。因此,低强度混凝土的胶凝材料用量比现在高,在适宜用量范围。水胶比一般在0.5以下,混凝土拌合物趋向高性能化,泌水现象不是很突出。坦诚地讲,笔者在此之前对泌水现象有思考,但研究的并不多,不是很深 I was engaged in the concrete operation of concrete quality control when the main use of P.O32.5 cement, cement dosage higher than P.O42.5 cement. The market size of commercial concrete is not large nowadays, the supply of admixture is not as tense now, the quality of fly ash is better and the dosage is higher. At that time the material cost is low, the price of concrete is higher, the competition is not intense now. Therefore, the amount of low-strength concrete cementitious material than it is now, in the appropriate range of dosage. Water-cement ratio is generally below 0.5, concrete mix tends to high performance, bleeding phenomenon is not very prominent. Honestly speaking, I had thought about bleeding phenomenon before, but not many studies, not very deep