Determination of the Mix Design Of Fresh Concrete from the Analysis of Hardened Concrete
When the concrete is damaged (cracking, lack of resistance), the quality of the concrete used is often questioned and in particular the respect of the Water/Binder reports vis-à-vis the standard EN 206-1.However, the results obtained are often surprising and always criticized...The objective of this work is to determine a reliable calculation method, from simple laboratory tests, to identify the initial mix design of the concrete (the cement dosage, the initial W/C ratio, the admixture content...) given measurements made in the hardened state.In the first section, the main components of the concrete, the concrete mix design and the relationship between the concrete mix design and its properties were studied.There is no doubt that the W/C ratio is the most important factor that strongly influences the strength and durability of concrete.Some methods of analysis of hardened concrete have also been studied.After analyzing the results of many other studies, we find the methodology to determine the cement content and the porosity.With other quantities (portlandite content, degree of hydration of cement...), they are important data to characterize the properties of concretes with respect to their durability.To reach the objective of the project, in the experimental section, it will be necessary to carry out physical tests (density, porosity...) and chemical (content of binder, degree of hydration) on concretes manufactured in the laboratory (controlled conditions) with different W/C ratios, different constituents (binder, admixture) and at different ages.The proposed approach is based on a comprehensive analysis that incorporates chemical analysis of the binder phase and bound water content measurements, porosity (void volume) and density of the mortar or concrete.These data then make it possible to calculate the cement and water dosages under certain hypotheses (occluded air, etc...).The validation of this method will be carried out on eight values of W/C varying from 0.5 to 0.8, and based on the complete mineralogical analysis of the mortars.
concrete mix design durability W/C ratio strength
Quoc Gia HOANG Quoc Vu(o)ng VU
Faculty of Civil engineering, Thuyloi University, Hanoi, Vietnam
国际会议
福州
英文
435-440
2018-11-04（万方平台首次上网日期，不代表论文的发表时间）