Abstract
Abstract The internal curing technology has been widely applied to high-strength concrete, for it can make the high-strength concrete marked by low shrinkage and durable frost resistance. The key to its extension and application lies in the reasonable mixing amount of internal curing materials. To address this problem, scholars have proposed a method for determining the water demand in internal curing; however, the water release of internal curing materials is difficult to obtain by measurement due to the mixing method. Therefore, this paper proposed a calculation model for the mixing amount of internal curing materials based on the modified MULTIMOORA method (Multi-Objective Optimization on the basis of Ratio Analysis plus full multiplicative form). First, different internal curing materials (super absorbent polymer (SAP), lightweight aggregate (LWA)) and pretreatment methods were selected to calculate their compressive strength, self-shrinkage and frost durability according to a proposed test scheme on the mixing amount of internal curing materials, and in such case, the comprehensive performance evaluation of the above indexes was turned into a multi-attribute decision-making problem. Second, the ordered weighted averaging (OWA) method and the entropy weight method were used to determine the subjective and objective weights of the indexes respectively, to eliminate the impact of outliers in the subjective evaluation values. Finally, the comprehensive performance of each test group was sorted using MULTIMOORA, and based on the sorting results and the calculation model, the mixing amount of internal curing materials was determined. The numerical example application results showed that the mixing amount of SAP curing material calculated based on the model herein was 1.276 kg/m3, and the mixing method adopted the pre-water absorption method with the total water-binder ratio unchanged. The numerical example evaluation results were in good agreement with the test results. The internal curing effect of SAP was better than that of LWA, and reached the best when the mixing amount was calculated at 25 times the water release rate and the requirement for the maximum total water diversion was met. The study may provide new ideas for extension and application of the internal curing technology.
Highlights
The “internal curing” was first put forward by American scholar Philleo [1] in 1991
Different internal curing materials (super absorbent polymer (SAP), lightweight aggregate (LWA)) and pretreatment methods were selected to calculate their compressive strength, self-shrinkage and frost durability according to a proposed test scheme on the mixing amount of internal curing materials, and in such case, the comprehensive performance evaluation of the above indexes was turned into a multi-attribute decision-making problem
The internal curing technology refers to adding internal curing materials to concrete under pre-stored water conditions to increase the internal humidity of the concrete through water release, thereby promoting the hydration of cementing materials and reducing the self-shrinkage of the concrete, and improving the overall performance of the concrete [2, 3]
Summary
The “internal curing” was first put forward by American scholar Philleo [1] in 1991. The internal curing technology refers to adding internal curing materials to concrete under pre-stored water conditions to increase the internal humidity of the concrete through water release, thereby promoting the hydration of cementing materials and reducing the self-shrinkage of the concrete, and improving the overall performance of the concrete [2, 3]. In practical applications, the amount of water pre-absorbed by internal curing materials is not totally equal to the amount of water released, and the latter is hard to obtain accurately during the hydration process, which leads to a great uncertainty in calculating the mixing amount of internal curing materials. To tackle this problem, this paper put forward a calculation model of internal curing materials mixed in high-strength concrete based on modified MULTIMOORA. The overall performance of internal curing materials was determined by MULTIMOORA evaluation method, and the optimal internal curing material and its mixing amount were obtained by an inverse model, which would promote the extension and application of internal curing materials
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
