Anti-crack performance improvement of concrete for prefabricated C50 bent cap concrete
This study tests the mechanical properties,deformation,and early anti-cracking performance of precast beam cap concrete.Using 3D simulation software,it analyzes the distribution of internal temperature and stress fields,focusing on the improvement effect of expansive agent and internal curing agent on the crack resistance of precast beam cap concrete.Results indicate that precast C50 beam cap concrete develops early strength rapidly but exhibits significant drying shrinkage,leading to a high risk of cracking.With the addition of 5％expansive agent and 0.1％internal curing agent,compressive strength increased by 4％～9％from 7～90d,while tensile strength and tensile modulus of elasticity rose by 2％～6％.Drying shrinkage deformation decreased by 10％～19％,and the peak negative pressure of capillary pores was reduced with a delayed peak occurrence.No visible cracks appeared in the flat plate cracking test until 48 h.Although the agents had minimal impact on the temperature field,they reduced the stress peak during stress concentration,delaying the maximum tensile stress by 11 hours compared to the control group,and increasing the crack resistance safety factor to 0.58.However,the risk of cracking remains significant,necessitating further measures to mitigate it.
万方数据
维普
