RETRACTED ARTICLE: Research on Construction Risks and Countermeasures of Concrete Dam

Abstract

The harsh environment will reduce the interlayer bonding quality of mass concrete and cause plastic cracking. These defects will seriously affect the safety and durability of the structure. This study tested the layer state (water content and penetration resistance), interlayer mechanical properties, and early-age crack resistance of concrete to evaluate the impact of extreme weather on concrete interlayer properties and crack resistance. Furthermore, the interlayer splitting tensile strength of concrete under different treatment measures (covering insulation quilts and artificial grooves) was analyzed to find a method to reduce the construction risk of mass concrete. At the same time, the early-age crack resistance of concrete under different treatment measures (covering insulation quilts and adding PVA fibers) was evaluated. The results showed that the interlayer splitting tensile strength of concrete decreased by 50%, 40%, 29%, and 70%, respectively, compared with bulk concrete under extreme weather conditions (high temperature, strong winds, steep descent in temperature, and short-time heavy rainfall). Covering insulation quilts can reduce the construction risk of concrete under extreme weather conditions such as high temperature, strong winds and steep descent in temperature. This is mainly due to the fact that insulation quilt reduces the impact of the external environment on the concrete and effectively prevents the evaporation of moisture inside the concrete. In addition, covering insulation quilts can reduce the total cracking area of concrete under extreme weather conditions (strong winds and dry-heat, strong winds and cold waves, and short-time heavy rainfall) by 85–100%. At the same time, adding PVA fibers can inhibit the generation and expansion of micro-cracks on the concrete surface. This is due to the bridging and cracking resistance of PVA fibers.