Abstract: In order to reduce the amount of cementitious materials in ultra-high performance concrete (UHPC), we prepared UHPC specimens containing coarse dolomite aggregate (CDA) and investigated the effects of CDA content and steel fiber volume on compressive strength, flexural strength, elastic modulus, uniaxial tensile property and abrasion resistance of UHPC. Results revealed that with the increase of CDA dosage, the elastic modulus improved significantly, the compressive and flexural strength of UHPC increased firstly but then decreased. On the one hand, as the volume of steel fiber increased, the uniaxial tensile property of UHPC were enhanced, wherein improving the compressive strength, first cracking strength, post cracking strength and energy absorption capacity of UHPC. On the other hand, the mass loss and depth of abrasion reduced with the increase of steel fiber content which represents the optimization of abrasion resistance of UHPC. When the dosage of CDA was 200 kg/m³ and the volume of steel fiber was 1.5%, the comprehensive performances of UHPC reached the optimum.

Key words: ultra-high performance concrete, coarse dolomite aggregate, uniaxial tensile performance, steel fiber, abrasion resistance