High Performance Concrete Early Crack Resistance Test Study In Arid Regions

High performance concrete has been gradually used widely at present, however, due to thehigh performance concrete water-binder ratio is low, less water consumption factors makes iteasier than ordinary concrete plastic shrinkage cracking, has become one of the focuses of theengineering. Ganhe reservoir panel high-performance concrete, based on xinjiang xinjiangthree net.as well tuen mun floor high strength high performance concrete as the researchobject, through the concrete early crack resistance test, is studied in the different environmentmaintenance method and maintenance starting time on the influence of high performanceconcrete plastic cracking, to improve the performance of high strength high performanceconcrete construction is discussed and the method of crack resistance. The results show thatthe(1) Compared to the laboratory and two kinds of construction site environment under theinfluence of the curing of concrete plastic cracking, found at the scene of the construction of adry, high temperature, wind environment, through the timely maintenance to reduce or avoidearly cracking of concrete surface effect is more obvious, therefore, the effect of maintenanceis more important.(2) In a dry, high temperature, wind environment, high performance concrete pouring ifthey are not in a timely manner after curing, concrete surface is easy to produce relativelylarge areas of the plastic cracking; Whether maintenance starting time of concrete plasticcracking and cracking degree significantly, the influence of concrete pouring should be within1hour after plaster molding curing of concrete surface coverage, can effectively prevent thecracks of the plastic.(3) Covering plastic film curing coating curing agent and curing the anti-cracking effect ofclose; In the final set of concrete cover wet blanket filling water in time, when the birth anddevelopment of cracks could be restrained effectively.(4) In the construction site and if there is no guarantee that early (1hour) to covermaintenance, steam spray concrete immediately after plaster reduction agent method canreduce the concrete surface moisture loss, make up for the concrete surface is not covered intime due to the lack of rapid water loss. But used alone cut steamed agent to resist concreteplastic cracking effect is not obvious, steamed reduction agent combined with coverage curingimmediately after the plaster gush steam reduction agent, at the same time as far as possible inadvance of covering plastic film or coating curing agent, can derate concrete plastic crackingeffectively.(5) Through laboratory tests and field construction found: low water-binder ratio, highstrength high performance concrete and its mixing water less, more consistency and highperformance concrete construction more difficult than normal (vibrating, plaster), its surfaceis also easier to dry crust, plastic cracks appear much earlier. In surface spraying mixtureduring the construction of a certain concentration of retarder solution, to improve theconsistency of large concrete construction plaster performance has obvious effect, and canprevent concrete surface crusting, delay the concrete surface is dry, is conducive to earlybreaks plastic cracking; In combination with surface spray retarder mixture dilution solutionmeasures, early surface maintenance, and final set for hydrating maintenance in time, caneffectively prevent early plastic cracking of high strength high performance concrete.