A New Multicoefficients Creep Model for Concrete

Abstract

Abstract The existing creep models for concrete are usually accompanied by complex calculations or a limited application scope because the factors that influence the creep behavior of concrete are numerous. A new, multicoefficients compressive creep model for concrete was proposed. This model is suitable for humidity from 3 % to 100 %, temperature from −20°C to 80°C, effective size from 20 mm to 500 mm, loading age from 1 day to 1,000 days, compressive strength from 15 MPa to 180 MPa, and stress level η ≤ 0.76. First, creep experiments were conducted on 188 concrete prisms under controlled room conditions and humidity conditions, which included different axial compressive strengths, different theoretical stress levels, different loading ages, and different load durations. Moreover, the linear creep coefficient model was obtained by regression analysis of the linear creep experimental data. Then the correction coefficients of concrete strength, loading age, temperature, humidity, and effective size of specimen on the creep behavior of concrete were obtained by fitting the 1,148 experimental data from references. Finally, the amplification coefficient formula of nonlinear creep was obtained from the relation between nonlinear convergences and linear creep experimental data, and the proposed creep model was verified by experimental data.