Modeling of the Reinforcement Minimum Spacing of Precast Concrete Using Grouting

The pull-out test of precast concrete connection system using grouting to find the characteristics and behavior of the connection system in resisting axial tensile forces. Besides experiments in the laboratory, it can also be simulated modeling using software Finite Element Method. The specimens modeling on the pullout test in this study used four bars, there are two rows and two columns configuration. The compression strength of concrete is 25, and 35 MPa and the grouting use Masterflow 810. The purpose of this modeling is to find the minimum distance of reinforcement required to avoid a collapse in concrete and grouting. The bars diameter is D16, D19, D22, D25, and D28. The bars spacing are 1.5D, 2D, 2.5 D, 3D, 3.5D, 4D also 5D, where D is the outer diameter of the grouting thickness of 2 times bars diameter. The constitutive modeling is using concrete damage plasticity theory. It is to identify the pattern of failure of the specimens. The results showed that the greater of bars spacing, the smaller the percentage of element failure. Concrete and grouting material damaged by tensile stress, where the most significant failure at 1.5D length about 15% -25% and the grouting element of 78% -95%. Recommendation of bars minimum distance to prevent the failure in concrete and grouting that is equal to 4D.