A sustainable approach in using construction and demolition waste materials in concrete

Abstract

Purpose The purpose of this paper is to investigate the potential use of construction and demolition waste materials (C&DWM) as an alternative for natural fine aggregates (NFA), in view to solve the disposal problems caused due to landfills. In addition, to evaluate its suitability as a sustainable material, mechanical and durability properties have been performed on different proportions of concrete blending and the results recorded were compared with the reference concrete values. Design/methodology/approach In this research, the NFA were replaced at the proportion of 25%, 50%, 75% and 100% of C&DWM with a constant slump range of 130 mm–150 mm. This parameter will assess the consistency of the fresh concrete during transportation process. The characteristics of the end product was evaluated through various tests conducted on hardened concrete samples, namely, compressive strength, flexural strength, depth of penetration of water under pressure, rapid chloride penetration test, carbonation test and ultrasonic pulse velocity (UPV) test. All results recorded were compared with the reference concrete values. Findings The results demonstrated that the use of C&DWM in concrete portrayed prospective characteristics that could eventually change the concept of sustainable concrete. It was noted that the compressive and flexural strength decreased with the addition of C&DWM, but nevertheless, a continuous increase in strength was observed with an increase in curing period. Moreover, the increase in rapid chloride penetration and decrease in UPV over time period suggested that the concrete structure has improved in terms of compactness, thus giving rise to a less permeable concrete. The mechanical tests showed little discrepancies in the final results when compared to reference concrete. Therefore, it is opined that C&DWM can be used effectively in concrete. Originality/value This study explores the possible utilisation of C&DWM as a suitable surrogative materials in concrete in a practical perspective, where the slump parameter will be kept constant throughout the experimental process. Moreover, research on this method is very limited and is yet to be elaborated in-depth. This approach will encourage the use of C&DWM in the construction sector and in the same time minimise the disposal problems caused due to in landfills.

Innovative approach for the protection of recycled concrete by biogenic silica biodeposition

“…The Spanish structural code for concrete [37], establishes a upper limit of P max = 30 mm for concrete to guarantee its durability. The value of Pmax = 18 mm obtained for Csamples indicates that the recycled concrete used in this investigation is already sufficiently water resistant to meet current standards and performs significantly better than other experimental mixes with similar percentages of waste concrete RAs, for example, Matar and Barhoun [62] recorded P max = 39 mm while results from as study by Quedou et al [63] gave this value as 25 mm. Furthermore, the value of P max found for D-samples was 25.4 % lower than that for C-samples.…”

Compressive Strength Of Concrete The Time Setting Of Application Of Plastiment® P-121 Additive Mixture

“…The definition of concrete compressive strength is the amount of load per unit area, which causes the concrete specimen to crumble when subjected to a certain compressive force produced by a pressing machine [8] [18]. Concrete compressive strength is the most important characteristic of concrete quality compared to other properties [19] [20]. The compressive strength of concrete is determined by setting the ratio of cement, coarse and fine aggregate, and water.…”

Effect of Particle Size and Morphology of Siliceous Supplementary Cementitious Material on the Hydration and Autogenous Shrinkage of Blended Cement

“…Due to the serious environmental problems posed by the production of cement, a series of green supplementary cementitious materials (SCMs) are being studied and developed to partially replace cement and thus decrease environmental pollution [ 5 ]. SCMs can be mainly classified into two categories: natural pozzolanic minerals (such as pozzolana, kaolin or metakaolin, and calcined clay) [ 6 , 7 , 8 ] and industrial by-products [ 9 , 10 , 11 ]. Considering their relatively low cost and the benefits to environmental protection, industrial by-products with high pozzolanic activity and/or hydration capacity, such as steel slag [ 12 ], slag [ 13 , 14 ], fly ash [ 15 , 16 ], and silica fume [ 17 ], are very suitable to be used in the development of cementitious composites as a substitute for cement.…”