Optimization Of Mix Proportion Design Of High Strength And High Performance Concrete

The high strength and high performance concrete is a novel and high qualitybuilding material, its advantages are high strength, durable, small deformation and so on,it has been widely used in modern engineering structures. As a composite multi-phasematerial, its performance is largely determined by the nature of the raw materials andtheir relative content, so mix proportion design is the key to excellent performance, theperformance requirements of high strength and high performance concrete are relativelycomplex. The classic design approach has been difficult to achieve it. How to optimizethe mix design of high strength and high performance concrete is the problem to besolved in today’s society.This paper studies the optimization design of high strength and high performanceconcrete, its strength grade is range from C60to C100. Combining with the presentstate of affairs about the mix proportion design of high strength and high performanceconcrete, the raw materials and performance of high strength and high performanceconcrete are studied and analyzed, and the theoretical basis is provided for high strengthand high performance concrete. The test results of high strength and high performanceconcrete of our project team and Zhao Ligou and them are summarized, the partialcorrelation analysis of the test data is performed by statistical software, the correlationdegree of every component and28days compressive strength, slump, on this basis,combination of experimental data analysis results and consideration of durabilityrequirement, the best ranges of water-cement ratio, sand ratio, polycarboxylic highrange water reducer, fly ash and silica fume are obtained, and they are as the constraintsof the optimization problem. Because complex nonlinear relationship between the raw material usage and performance of concrete is existing, the multi-parameter nonlinearmodel between the raw material usage and performance of concrete need to beestablished, according to Taylor series, using polynomial to approach it. With limitedexperimental data in the paper, the quantity of model variables is reduced to five fromseven. Regression analysis of47set of experimental data is performed by statisticalsoftware, the prediction equation of28days compressive strength and slump of highstrength and high performance concrete are obtained, and prediction results andexperimental results are compared, it is discovered that the fitting precision of theprediction equation meets demand.Based on strength and workability of high strength and high performanceconcrete, its mix proportion is optimized. In addition to the strength and slumpprediction equation, the cost equation is also taken into account, the multi-objectiveoptimization function of the mix proportion design of high strength and highperformance concrete is established. According to sequential quadratic programmingmethod, the problem of the mix proportion design is solved by optimization toolbox inMATLAB. The optimization result and experimental result are compared, it isdiscovered that the optimization idea not only to achieve the performance optimizationof high strength and high performance concrete, and also to achieve the minimum costof concrete. Considering the durability of high strength and high performance concrete,the root of the cause’s concrete durability problems is analyzed, the materialcomponents of high strength and high performance concrete are selected. Theimpermeability of high strength and high performance concrete is used to reflect thedurability, through five groups tests of high strength and high performance concreteimpermeability, the effect of water-cement ratio, silica fume and fly ash to the highstrength and high performance concrete is analyzed.The results of this paper will provide optimization basis of the high strength andhigh performance concrete for the optimization of concrete member, concrete structure,and even the whole piece of concrete construction, and provide an optimal mixture ratioof concrete directly for the majority of engineering and technical personnel, technicalstaff can obtain reference in the concrete materials selection. The optimization result ofthis paper can be directly applied to high strength and high performance concrete structure, the most basic and optimal materials can be provided to create a betterproject.