Preparation Of Concrete For Products In Different Ambient Temperatures

With the rapid development of construction industrialization,the demand for concrete products is increasing.When producing concrete products,there is an urgent need to solve the problem of how to increase the early compressive strength to demolding strength.Concrete product factories generally use steam curing to improve the early compressive strength of concrete products.However,this curing method will increase the production cost of concrete products and damage concrete products;therefore,some factories choose to use steam-free curing methods to prepare concrete products,but when the external environment temperature is low,it is difficult for the steam-free curing concrete to reach the demolition within the specified time.The strength of the mold cannot be removed on time.Therefore,this article studies the preparation technology of product concrete under different ambient temperatures to achieve the purpose of super early strength and early mold removal,which has certain significance for the development of the concrete product industry.This article mainly carried out three aspects of research:First,study the setting time of different ambient temperatures(15℃,20℃,25℃,30℃)and different early strength components(early strength agent,sulfoaluminate cement)on cement-based materials,Workability and compressive strength,analyze the strength and other performance development laws;second,study the effect of water-binder ratio,cement dosage and sand rate on concrete workability and compressive strength at different ambient temperatures,and explore early strength agents and sulfur Optimization of compressive strength of concrete with aluminate cement and fly ash,so as to determine the preparation technology of product concrete in different ambient temperatures;finally,according to the preparation strategy of product concrete in different ambient temperatures,combined with economic analysis,rationally arrange the factory Class system.The results show that when the ambient temperature is higher than 25℃,the early compressive strength of the cement-based material increases rapidly.The early strength agent can effectively improve the compressive strength of the cement-based material.Increasing the amount of cement can significantly increase the early compressive strength of the cement-based material;When the temperature is lower than 25℃,the early compressive strength of the cement-based material increases slowly.Adding 5%early strength agent and increasing the amount of cement cannot effectively improve the early compressive strength of the cement-based material.Sulphoaluminate cement can reduce the workability of cement-based materials in different ambient temperatures,greatly promote the development of early compressive strength,and with the increase of ambient temperature,sulfoaluminate cement has an early compressive strength on cement-based materials the increase is increased.Changes in ambient temperature,cement dosage,and sand rate have little effect on the workability of cement-based materials,and the workability of cement-based materials can be maintained well.When the ambient temperature is higher than 25℃,when the amount of cement is above 400kg/m~3,the concrete reaches 15.0MPa strength,without adding early strength components,the time required is 10～12h;when 5.0%early strength agent is added,the time can be shorten to 8～10h;when adding 5.0%early strength agent and 3.0%sulfoaluminate cement,the time can be further shortened to 6～8h.When the ambient temperature is lower than 25℃and the cement dosage is 400kg/m~3,it is difficult for the concrete to reach 15.0MPa strength in 12 hours,increase the cement dosage to450kg/m~3,and add 5.0%early strength agent and more than 7.0%sulfoaluminate cement.The 8-10h age compressive strength of the prepared concrete can exceed 15.0MPa.Compared with the steam curing concrete preparation cost of 394.7 yuan/m~3,when the ambient temperature is 30℃and above,this test concrete can be demolished within6h～8h,the cost is reduced by 9.5%,the factory can arrange 3 shifts/d,ambient temperature When it is 25℃,the concrete used in this experiment can be demoulded within 8h,the cost is reduced by 3.1%,and the factory can arrange 2 shifts/d;when the ambient temperature is 20℃and 15℃,the use of this ratio can make the product use Concrete is demolished within 8h and 10h,the cost is reduced by 1.3%and increased by0.2%,and the factory can achieve 2 shifts/d.The concrete preparation technology studied in this article can avoid the use of steam curing,thereby avoiding the problems of high cost and deterioration of concrete products caused by steam curing.When the ambient temperature is reduced,the early compressive strength of the concrete used for the steam-free curing products does not reach the standard,which causes the problem that the mold can not be demolished.It is possible to scientifically and rationally choose different preparation strategies in different ambient temperatures,so that the concrete product reaches the demolding strength within the early12h,So that the factory can reasonably arrange the work system and optimize the economic benefits.