应用微波蒸压技术的混凝土强度快速测定方法

Fast estimating concrete strength method applying microwave autoclave curing technology

为了快速测定混凝土强度,将微波技术应用到传统的蒸压养护工艺中,自行设计和制作了小型微波蒸压釜。通过试验得出了釜腔内温度压力大小、恒温恒压养护时间对混凝土早期强度的影响规律,进而总结出微波蒸压养护条件下混凝土快速养护制度。通过15批次（5种配合比）不同强度等级混凝土的微波蒸压养护和标准养护对比试验,建立了微波蒸压养护条件下的混凝土强度线性和非线性回归模型,模型中考虑了加速养护混凝土强度和混凝土水灰比,具有较好的相关关系。试验分析发现：运用微波技术,可以均匀、迅速地提高混凝土内部温度,减小温度应力,使混凝土1 h内获得较高（28 d强度40%～50%）、稳定的早期强度,可以作为预拌混凝土生产企业和施工现场进行强度控制和配合比调整时的依据。

In order to estimate concrete strength quickly, microwave was applied to the conditional autoclave curing. Small microwave autoclave suitable for the microwave autoclaved were self designed and made. By experiment research, the effect laws of temperature in autoclave and constant temperature curing time on the early strength of concrete were investigated, and rapid curing system was summa- rized on the condition of microwave and autoclave.By the contrast test of microwave autoclave curing and standard curing of 15 batches of different strength grade concrete, the linear and nonlinear regression model of concrete strength determination were established with better correlativity on the condition of microwave and autoclave. Concrete strength accelerated of curing and water - cement - ratio was considered in the model. It was found that the internal temperature of concrete would be uniformly, rapidly improved by microwave, and the temperature stress would be reduced.The high and stable early strength of concrete （ 40- 50 percent of 28 d strength）was obtained within 1 hour, which can be used as the strength controlling and the mix proportion of adjustment to the concrete premixing enterprises and construction concrete producing sites.