Abstract

The effect of nanosilica under the influence of dispersing agents on the fresh empirical and fundamental rheological properties of self-compacting concrete (SCC) is a complex phenomenon which has been investigated in this paper. Models to predict the rheological properties of nanosilica blended SCC are also lacking to avoiding/saving comprehensive and costly rheology laboratory trials mainly when these tests are unavailable or limited. To these ends, 315 laboratory tests were performed on 15 blended SCC mixtures, manufactured using five nanosilica dosages, 0%, 0.5%, 1%, 1.5%, 2%, and three dispersing superplasticizer dosages, 0.62%, 0.66%, 0.70%, by weight of cement. Fundamental rheological properties of the SCC mixes were assessed by using a rotational concrete rheometer based on the nonlinear modified Binghamian model. Results showed that SCC mixes are sensitive to nanosilica and superplasticizer admixtures producing a complex non-linear effect on their empirical and rheological properties. Based on these trends, eleven empirical models were proposed to predict the fresh empirical and rheological properties of the SCC mixes. A statistical analysis demonstrated the good fitting of the proposed models with the measured properties of SCC mixes during the laboratory trials. These models could serve for design and production of nanosilica blended SCC as alternative approach.

摘要

在分散剂的影响下，纳米二氧化硅对自密实混凝土 (SCC) 的新鲜经验和基本流变特性的影响是一个复杂的现象，本文对此进行了研究。预测纳米二氧化硅混合 SCC 的流变学特性的模型也缺乏避免/节省全面和昂贵的流变学实验室试验，主要是当这些测试不可用或有限时。为此，对 15 种混合 SCC 混合物进行了 315 次实验室测试，这些混合物使用五种纳米二氧化硅剂量 0%、0.5%、1%、1.5%、2% 和三种分散减水剂剂量 0.62%、0.66%、0.70% 制造, 按水泥重量计。SCC 混合物的基本流变特性通过使用基于非线性修正宾汉姆模型的旋转混凝土流变仪进行评估。结果表明，SCC 混合物对纳米二氧化硅和高效减水剂混合物敏感，对其经验和流变性能产生复杂的非线性影响。基于这些趋势，提出了 11 个经验模型来预测 SCC 混合物的新经验和流变特性。统计分析表明，在实验室试验期间，所提出的模型与 SCC 混合物的测量特性非常吻合。这些模型可以作为替代方法用于纳米二氧化硅混合 SCC 的设计和生产。统计分析表明，在实验室试验期间，所提出的模型与 SCC 混合物的测量特性非常吻合。这些模型可以作为替代方法用于纳米二氧化硅混合 SCC 的设计和生产。统计分析表明，在实验室试验期间，所提出的模型与 SCC 混合物的测量特性非常吻合。这些模型可以作为替代方法用于纳米二氧化硅混合 SCC 的设计和生产。