超高强泵送混凝土的应用越来越广泛,但还存在配合比设计尚无相应规范参考、配制过程大多依靠经验、技术尚不成熟等问题。为满足工程采用超高强泵送混凝土的要求,阐明关键配合比参数对超高强泵送混凝土抗压强度的影响规律,通过系统研究水泥品种、胶凝材料用量、矿物掺合料种类、水胶比和碎石种类等配合比参数对混凝土抗压强度的影响规律,配制出满足工程要求的C100超高强泵送混凝土。研究结果表明: 配制C100超高强泵送混凝土,水泥品种和碎石种类是2个关键参数,宜选用P·Ⅱ52.5水泥和母岩强度高的碎石;
在本试验条件下,胶凝材料用量宜为640 kg/m3,矿物掺合料掺量宜为25%(宜选用含硅灰的掺合料体系),水胶比宜为0.20。
The application of ultrahighstrength pumping concrete is becoming more and more widespread, but
there are still problems, the design of mixing proportion does not have
corresponding specifications, the preparation process mostly depends on
experience, and the technology is not yet mature. In order to meet the using
requirements of ultrahighstrength
pumping concrete, and to clarify the influence of key mixing proportion
parameters on the compressive strength of ultrahighstrength pumping concrete, the influence law of preparation
parameters such as cement type, the amount of cementing material, the type of
mineral admixture, the watertobinder ratio and the gravel type on the concrete compressive
strength are systematic studied, and the C100 ultrahighstrength pumping concrete that meets the engineering requirements is
prepared. The study results show that: (1) For the preparation of C100 ultrahighstrength pumping concrete, the type of
cement and the crushed stone are the two key parameters, and the P·Ⅱ 52.5 cement and the rock with high strength of the parent rock
should be selected. (2) Under the experimental conditions, the dosage of
gelling material should be 640 kg/m3, the amount of
mineral admixture should be 25% (silicon ashcontaining
admixture system should be used), and the waterbinder
ratio should be 0.20.