Micro Silicon Powder-basalt Fiber Concrete Mechanical Properties And Crack Resistance

With the rapid development of The Times,in today's building materials,concrete gradually to the development trend of high pressure,high tensile,high fluidity,and hope to long-term keep concrete,high strength,high toughness and high permeability etc.At the same time,it is necessary to change the construction process in the concrete structure.Therefore,high performance concrete is born,the main development direction of high-performance concrete is modified concrete,and fiber concrete is the main content of the development of high-performance concrete.Because the fiber in the fiber concrete can change the brittleness of concrete itself,on the strength of the main performance in order to improve the tensile strength and flexural strength of concrete,at the same time can improve the concrete cracking resistance and toughness,represented by basalt fiber of fiber concrete now have good feedback in practical application.Microsilica powder is a kind of natural mineral raw material,its own filling effect,ash effect and interface effect can increase the density of concrete,thus enhancing the strength of concrete.In this paper,the effects of the two on the physical and mechanical properties of the high strength concrete and the anti-cracking performance were studied by using the microsilica powder and the basalt fiber as the research object.In the experiment,the microsilica powder was used to replace the cement dosage,with the dosage of 5%,7%,10%,12%and 15%,and the basalt fiber adopted the external doping method,with the dosage of 1kg/m~3,2kg/m~3,3kg/m~3,4kg/m~3,and 5kg/m~3.The main work and results are as follows:1,to adopt a magnitude of 42.5 cement,medium sand and 5 mm to 20 mm melon seed piece of stone in 0.36 water-binder ratio made of basalt fiber reinforced concrete under 1 kg/m~3,2 kg/m~3,3 kg/m~3,4 kg/m~3,5 kg/m~3of basalt fiber,through the press,the concrete compressive strength increased slightly,3 kg/m~3 basalt fiber concrete peak intensity values.The tensile strength and flexural strength of concrete are obviously improved,and the strength value of 3kg/m3 basalt fiber concrete peaks.2,through the mixing method,with 5%,7%,10%,12%and 15%respectively than the quality of micro silicon powder to replace cement,under 0.4 water-binder ratio of micro silicon powder concrete,through the press measure,obviously improve the compressive strength of concrete,peak under 10%dosage of micro silicon powder.The tensile strength and flexural strength of concrete are improved slightly.3,Using the method of orthogonal experiment,the basalt fiber and mineral materials mixed with micro silicon powder,find out the best dosage ratio,found that 3kg/m~3 basalt fiber and 10%from micro silicon powder mixing with concrete compressive strength,splitting tensile strength and flexural strength reach maximum.4.The influence of basalt fiber and microsilica powder mineral admixtures on the anti-cracking performance of concrete was investigated through the ring test method.The study found that basalt fiber and micro silicon powder can improve the cracking resistance of concrete,including basalt fiber raise larger,when the basalt fiber and micro silicon powder mixed with mineral admixtures,the resistance to cracking of concrete performance improvement effect is most obvious.