一、前言众所周知,在原材料确定之后,混凝土的强度主要取决于水灰比;在保持一定流动性的条件下,要提高其强度,就须增加单方的水泥用量,这不仅会增加成本,而且会使混凝土的温升提高,因而对要求高强度的大体积混凝土十分不利。于是就提出了这样的问题:在水灰比一定的条件下,混凝土的强度还能不能提高?如若在这点有所突破,必能取得较好的技术经济效果,一定会促进混凝土的技术进步。为此,在混凝土破坏机理研究的基础上,开展了加强界面粘结的工艺措施研究,其中包括水泥裹砂混凝土和净浆裹石混凝土的研究。水泥裹砂虽然可使水分向界面集中的现象有所减缓,利于加强石子与水泥石的粘结,因而混凝土强度可得到一定程度的提高,但水泥裹砂难于在石子表面形成低水灰比的净浆硬壳。因而其强度提高的幅度受到限制,且易产生波动。根据混凝土破坏机理的研究,证明石子与水泥石的界面粘结是混凝土中最薄弱的环节。可以设 I. Preface It is well known that after the raw materials are determined, the strength of concrete depends mainly on the water-cement ratio; under the condition of maintaining certain mobility, to increase its strength, it is necessary to increase the amount of unilateral cement, which will not only increase the cost, but also increase the cost. Increasing the temperature rise of the concrete is very disadvantageous for a large volume of concrete that requires high strength. Therefore, the question is raised: Under certain conditions of water-cement ratio, the strength of concrete can not be improved. If there is a breakthrough at this point, it will be able to achieve a better technical and economic effect, and it will certainly promote the technical progress of concrete. . For this reason, on the basis of the research on the mechanism of concrete failure, a study was carried out to strengthen the interfacial bonding process, including the study of cement-wrapped concrete and mortar-wrapped concrete. Although cement sands can slow down the concentration of water at the interface, which helps to strengthen the bond between stone and cement, the concrete strength can be improved to some extent, but cement sand is difficult to form a low water-cement ratio on the surface of the stone. Paste hard shell. Therefore, the strength of its improvement is limited and it is easy to fluctuate. According to the research on the failure mechanism of concrete, it is proved that the interface bonding between stone and cement stone is the weakest link in concrete. Can be set