Original scientific paper
Concrete crack potential predictions with the aid of a novel plastic ring, electrical resistivity and setting time
Samaila Muazu
; Huazhong University of Science and Technology, Wuhan China
Wei Xiaosheng
; Huazhong University of Science and Technology, Wuhan China
Abstract
Hydration and restrained shrinkage crack behaviours of different concrete grades were independently monitored using a non-contact electrical resistivity apparatus and a novel plastic ring mould respectively. The electrical resistivity curve trend is similar for all the concrete samples, in which the lowest concrete grade has the highest resistivity until reaching acceleration point which was then overtaken by the highest concrete grade. Four different hydration periods were identified upon which the hydration process can be based; these periods are classified into dissolution, induction, acceleration and deceleration periods. Also, initial and final setting times for the samples were examined, which confirmed that the decreasing rate of resistivity development for the lower concrete grade corresponds to its initial setting time range. Restrained shrinkage crack result shows that the highest concrete grade propagated cracks earlier than the lowest concrete grade and thereby the higher cracking potential of higher strength mixture was confirmed. Linear fitting was then developed to estimate concrete crack potential based on its electrical resistivity. Hence, both electrical resistivity measurement and novel plastic mould (which is very cheap, user-friendly and fast filled) are hereby proposed as a convenient alternative means of assessing concrete cracking potential.
Keywords
concrete; electrical resistivity; restrained shrinkage crack; setting time
Hrčak ID:
181511
URI
Publication date:
16.5.2017.
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