Shear behaviour of reinforced concrete beams utilizing waste marble powder

Today, it has been determined that waste marble dust (WMD) is not evaluated and therefore creates environmental problems. For this reason, in this study, the usability of WMD in different proportions, in which waste materials are evaluated, was investigated. Thus, it is aimed to eliminate the existing environmental problems by ensuring the use of WMD in reinforced concrete beams (RCBs). Pursuant to this motivation, an experimental program was carried out on 15 shear deficient RCBs, considering different WMD and stirrup spacing. While the proportion of WMD in the RCBs was chosen as 10%, 20%, 30% and 40% by weight, respectively, the stirrup spacing was considered as 270 mm, 200 m, and 160 mm. Concrete compressive strength (CCS) is generally adversely affected while WMD is used instead of cement at 10% or more rates. In RCB samples with the stirrup spacing of 270 mm, 200 mm, and 160 mm, 10%, 20%, 30%, and 40% WMD additives reduced the bearing capacity of the RCBs compared to the reference sample. It has been observed that ACI 318 (2019) and EC2 (2004) design regulations demonstrate excellent performance (maximum 85% success) in estimating shear strength up to 20% marble dust admixture in RCBs where the stirrup spacing is 200 mm and 160 mm. The results revelaed that using up to 5% of WMD instead of cement has approximately no negative influence on the CCS. Nevertheless, if this percentage is chosen as 10% or more, it has been found that the CCS is commonly destructively affected.

Automated summary

The usability of waste marble dust (WMD) in different proportions was investigated for the purpose of eliminating environmental problems in reinforced concrete beams (RCBs). The results showed that the addition of WMD additives negatively affected the bearing capacity of the beams. The design regulations of ACI 318 (2019) and EC2 (2004) performed well in estimating shear strength in RCBs with stirrup spacing of 200 mm and 160 mm.