Preparation Of Reactive Powder Concrete And Research On Impact Behavior

RPC was a high strength, low brittleness, high toughness, high durability, low shrinkage and creep properties, and good volume stability of cement-based composite material which was first developed by the French company Pierre Richard BOUYGUES research team in 1993. It is the second high-strength, high-performance concrete after the new type concrete. RPC will be used widely in the civil engineering, oil, nuclear energy and power, municipal, marine and other engineering and military facilities due to its superior performance, but the high price and some uncertain properties hinder its wide application in practical engineering. Under the national situation of the subject, this paper produced high performance RPC using common materials and simple domestic conservation system, and studied its impact behavior, which produced domestic market reference for this new material.The subject was divided into two parts, in the first part, the best proportion was selected and the RPC material was prepared, in the second part, the impacting behavior of RPC material was researched.A new method for preparing reactive powder concrete was proposed based on studying the orthogonal theory deeply. In the method the best matrix of RPC material was selected through orthogonal design theory, and then the dosage of steel fiber was optimized by experiments. By using 42.5R cement, fly ash, silica fume, general river sand, polycarboxylate superplasticizer and steel fibers, RPC material which reaches compressive strength of 193.8 MPa and flexural strength of 38.6 MPa was prepared in this paper.Impacting behavior and damage evolution were studied of RPC specimens with different steel fiber volume fraction at 0%, 1%, 2%, 3%. The result showed that RPC matrix was significantly improved by steel fiber on the compressive strength, flexural strength, flexural toughness and impact toughness. Considering of economy and pragmatism, the flexural toughness seemed to be better with 2% dosage of steel fiber, and the impact toughness seemed to be better with 3% dosage of steel fiber. Continuous the time of ultrasonic wave on the damage detection showed that: The impact damage curves of mixing fiber concrete D values have improved 1.1~3.5 times near the ultimate failure than plain concrete. The addition of steel fibers improves the absorption of impact energy of RPC.The surface cracks were observed by stereo microscope during the impact process, which provided a factual basis for revealing the toughening mechanism of steel fiber RPC.