Paper Title
The Reinforcement Minimum Spacing of Precast Concrete Using Grouting

Abstract
- 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 simulatedmodeling using software Finite Element Method.The specimens modeling on the pull out test in this study used four bars, there are two rows and two columns configuration. The compression strength of concrete are 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 collapse in concrete and grouting. The bars diameter of specimens are D16, D19, D22, D25 and D28. Thebars 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 the specimens. The results shown that the greater of bars spacing, the smaller the percentage of elementfailure.Concrete and grouting material is damaged by tensile stress, where the largest failure at 1.5D lengthabout 15% -25% and the grouting element of 78% -95%.Recommendation of bars minimum distance to prevent of failure in concrete and grouting that is equal to 4D. Keyword- Pull-out Test, Bars Minimum Spacing, Finite Element Method, Concrete Damage Plasticity