Compressive strength assessment of recycled aggregate concrete using Schmidt rebound hammer and core testing

Abstract

The main objective of this study was to estimate the compressive strength of recycled aggregate concrete (RAC) by means of Schmidt rebound hammer and core testing. The use of recycled aggregate in concrete has been shown to lead to a decrease in the construction cost and it can reduce the burden on the environment by saving natural aggregates. On the other hand, some nondestructive and semi-destructive techniques, such as Schmidt rebound hammer and core testing, are long-established methods for strength estimation of materials. Thus, the present study intended to obtain the compressive strength of RAC using these methods and then compare it with the results of 150 mm cube specimens. To achieve this goal, after producing concrete mixes with 70% replacement of recycled coarse aggregate, 96 cube specimens and 8 concrete slabs were cast to perform Schmidt rebound hammer, core and cube testing. In addition, the combination of the methods was used to obtain correlations between Schmidt rebound hammer and core testing. The results demonstrate that a multi-variable equation using these tests' results can efficiently predict the compressive strength of RAC and conventional concrete and is more promising than single-variable equations based on the Schmidt rebound hammer test results.

In-situ strength estimation of polypropylene fibre reinforced recycled aggregate concrete using Schmidt rebound hammer and point load test

“…The results given by Grieb [13] showed that the rebound number of concrete materials with a specific type of aggregate was different to that with the same type of aggregate, provided from another source, while the difference between the data of Schmidt hammer test at various locations of a concrete element was negligible as reported by Xu and Li [14]. In 2019, Kazemi et al [3] combined the results of Schmidt rebound hammer with the core testing method to estimate the compressive strength of a limited number of concrete samples made by the partial replacement of natural aggregates with recycled coarse aggregate (RCA). As per the results, there was a strong correlation between Schmidt rebound hammer and the core testing method to reliably estimate the in-situ strength of concrete.…”

“…Over the last decade, the estimation of the in-situ strength of specific types of concrete materials such as recycled aggregate concrete has drawn much attention from researchers owing to the difference between the manufacturing conditions of existing concrete at the construction sites and those of standard samples in the laboratory. Therefore, partially and nondestructive testing methods have been proposed to estimate the on-site strength of concrete materials [1][2][3][4][5][6]. The point load test (PLT), as one of the partially destructive testing methods, includes two concentrated point loads applied to the lateral surface of the core specimen.…”

Effect of the curing type on the mechanical properties of lightweight concrete with polypropylene and steel fibres

“…The overuse of natural aggregate in the construction sector has harmed the environment in recent decades, and it is estimated that about 7.5 billion tonnes of aggregates are annually consumed by the concrete industry [1][2][3][4][5]. This environmental issue can be somewhat solved by partial replacement of natural aggregates with artificial lightweight aggregates in the building process [6][7][8][9][10].…”

Retracted: Ranking of the most influential parameters for compressive strength of no‐slump concrete prediction by neuro‐fuzzy logic

“…The use of recycled aggregate in concrete has been shown to lead to a decrease in the construction cost and it can reduce the burden on the environment by saving natural aggregates. 4 The abstract roller-compacted concrete (RCC) is a zero slump concrete comprising the same materials as that of conventional Discussion on this paper must be submitted within two months of the print publication. The discussion will then be published in print, along with the authors' closure, if any, approximately nine months after the print publication.…”