基于RSM的碱矿渣混凝土断裂性能研究

Fracture Properties of Alkali--Slag Concrete Based on Response Surface Methodology

采用断裂试验、响应曲面法（RSM）、Design Expert软件、B0xBegnken试验设计方法研究了Na2Si03和NaOH复合激发矿渣混凝土ASC的断裂性能，构建了断裂韧度的RSM模型，建立了溶胶比、矿渣用量及龄期对ASC断裂韧性的影响规律、起裂断裂韧度K是与失稳断裂韧度K玉的关系、溶胶比及矿渣用量对ASC断裂韧性的影响规律，分析了溶胶比和矿渣用量对ASC断裂韧性的影响机理。结果表明：ASC的断裂韧性RSM模型拟合程度良好，溶胶比、矿渣用量、龄期对断裂韧性影响显著程度为矿渣用量〉龄期〉溶胶比，矿渣用量和龄期的交互作用最显著，KQIC约为KSIC的50％～70％，断裂韧性随溶胶比或矿渣用量增大而减小，这是由于溶胶比提高，碱矿渣反应更激烈，降低了ASC内部密实度和解聚反应，而胶凝材料用量增加，有效水胶比相对减小，后续水化受限，部分矿粉未参与反应，从而降低了ASC的韧度。

Fracture properties of alkali--slag concrete （ASC） prepared by using slag and Na2 SiO3, NaOH complex activa- tor were investigated byfracture tests, response surface methodology （RSM）, Design Expert software and Box-Benhnken design （BBD） . RSM models of fracture toughness, influence rules of solution--cement ratio （S/C）, dosage of slag and time on fracture toughness, the relation of unstable fracture toughnessKSIC between initial fracture toughnessKQIC , influence mecha- nism of S/C and dosage of slag on fracture toughness all were established. The results show that RSM models of ASC fit well and regresses significantly, influence extent of KS andKQIC was dosage of slag〉time〉S/C, alternant reaction of time and dos- age of slag was the most distinct; KQIC was about 50%-70% of Ks , fracture toughness of ASC was decreasing with increas- ing of S/C and dosage of slag, alkali and slag reacted more strongly with increasing of S/C, which can reduce the inner com- pact degree and depolymerizing reaction, At the same time, effective S/C was reduced with the increasing of dosage of slag, which can limit the following hydration reaction and make only part of slag Participate in the hydration, all the above can re- duce the fracture toughness of ASC.