Rice Husk Ash High-performance Concrete Durability Performance Test Research

Reform and building energy conservation building materials has become the basic state policy of our country, meet the building energy conservation national standards of new type structure material, the mission of materials has become a scientific research workers. Development of green high performance durability of concrete, it is through constant of the additives and composite materials to develop the study. Because of rice production in China is big, the annual capacity of three thousand tons of chaff can reach more than three thousand, from the development of green thermal insulation of concrete, reduce environmental pollution, improve the utilization ratio of rice husk ash multiple requirements, research and development of rice husk ash high-performance concrete has become a new topic these days. Rice husk ash concrete not only can be used as the channel lining material, and can be used as a kind of green environmental protection heat preservation material. The additive rice husk ash not only can improve the compactness of concrete itself, also to a certain extent, saving the cement. According to the different properties of rice husk ash, new type of green environmental protection concrete development research is currently a major focus in the research, but also has remarkable economic benefits and environmental benefits, to support local economic development has important significance.In this paper, the influence law of rice husk ash on the concrete performance as the main purpose of study, through the orthogonal experiment, the rice husk ash content, water/cement ratio, sand ratio, five factors affect the performance of concrete, such as optimizing the water-binder ratio, sand ratio and dosage of rice husk ash, fly ash and silica fume. To the benchmark set as a comparative object, studies the optimization group, single mixed rice husk ash on the concrete compressive strength, thermal properties, the influence law of anti-freeze properties such as permeability. The main results were as follows:(1)Through the orthogonal experiment, the optimal ratio of rice husk ash concrete optimizing the A3B3C3D2E2:water cement ratio of0.4, rice husk ash content is18%,15%dosage of fly ash, sand rate was40%, the dosage of silica fume3%, the concrete compressive strength can reach68.03MPa, meet the strength reliability of95%, and the optimal mixing proportion of concrete performance, good mechanical properties and durability.(2) Orthogonal experiment results show that under the standard curing, water-binder ratio, the rice husk ash content and so on various factors the influence of28D compressive strength of concrete significantly order:A (water-binder ratio)> E (silica fume)> B (rice husk ash)> C (fly ash)> D (sand ratio); Effects on the tensile strength of28D significant order:A>B>C>D>E; Impact on the28D compressive ratio of significant order:A> B> C> D> E; In dry curing conditions, various factors the influence of28D compressive strength of concrete significantly order:E (silica fume)> A (water-binder ratio)> C (fly ash)> B (rice husk ash)> D (sand ratio); Effects on the tensile strength of28D significant order:A>E>C>B>D; Impact on the28D compressive ratio of significant order:C >A>B>D>E.(3) Determination of coefficient of thermal conductivity of concrete through experiment showed that the conditions, compared to baseline group J and optimal Z, Z minimum thermal conductivity, the amplitude decreases by21.66%. Dry conditions, compared to benchmark group J and optimal Z, Z minimum thermal conductivity, the amplitude decreases by29.26%. Showed that rice husk ash content of10-20%of the heat transfer ability of the optimal set of concrete is relatively slow, low thermal conductivity, heat preservation and heat insulation for rice husk ash concrete ability provides a theoretical basis. And three groups of experiments in the dry and the two kinds of thermal conductivity were similar, curing conditions to do further research.(4) Concrete impermeability test showed that the mixed rice husk ash, fly ash and silica fume concrete compared with other group, in contrast, on the conditions and under the condition of dry raise relative permeability coefficient of concrete are reduced, a drop of35.98%and47.11%respectively, showed that mixed rice husk ash, fly ash and silica fume can obviously improve the permeability resistance of concrete. The optimal group under the condition of dry raising concrete and relative permeability coefficient than the permeability coefficient under the condition of low, indicates that under the condition of dry raise impermeability of concrete performance is the raise good conditions.(5) From concrete anti-freezing experiments can be concluded that:under the condition of two kinds of curing, mixed rice husk ash, fly ash and silica fume concrete relative dynamic elastic modulus is significantly higher than J two groups, and similar decline curve, showed that mixed with rice husk ash significantly improve the frost resistance of concrete. The keep Z group relative loss modulus than the dry Z group under the condition of1.18%. Based on the relationship between the relative loss modulus of concrete:Z>D>J, so concrete freezing-thawing resisting ability of sequence is Z> D> J.