Investigation And Analyses On The Early Forecasting Of Concrete Strength

Concrete strength, the core technique parameter in concrete quality control, is not only an important basis for structural design and construction but also one of the most important performances. Early determination and prediction about concrete strength receives much attention from each countries engineer and technician, through a lot of system researches, and have achieved considerable results. However, the quality of concrete is influenced by material machinery, methods and environment. Therefore, when forecasting 28d the compressive strength of concrete, prediction formulas will be different according to various factors. For raw materials usually used in specific areas, there should establish the corresponding forecast formula, but many forecasting formulas are established under the experimental conditions, thereby ignoring the impact on the development of concrete strength from temperature difference between the natural conditions and the standard conditions. Taking engineering practice into consideration, this paper makes a study on methods forecasting concrete 28d compressive strength though that of 3d, 7d under the standard curing conditions, and works out the most suitable method for early forecasting about concrete in Lu-Nan area.First of all, with the actual choice of four water-cement ratio of Ordinary Portland Cement we tested concrete strength of 3d, 7d and 28d, established a mathematical prediction model according a unary regression analysis on results, and made a theoretical analysis, which provides a theoretical basis for the early forecast for China's Lu-Nan area in the Ordinary Portland Cement concrete strength.Secondly, the discussion was made here on the main principles and the development process of the maturity as well as the establishing process of the formula for calculating the new maturity. Maturity is important in practice. It is a convenient and effective way to use the maturity rules to estimate the strength of concrete, especially giving a good guidance on forecasting the actual concrete strength onsite under the non-standard curing condition. Using test data on early forecasting of concrete strength, along with the Ordinary Portland Cement concrete forecasting model under the standard conditions and non-standard curing conditions, which is the application of new maturity, we set up an early forecasting method on the strength of concrete by the integration of single linear of the unary regression model and the maturity model after verifying the accuracy of their presumption through test datum.