Influence of particle size distribution of conventional fine aggregate and construction demolition waste aggregate in Portland cement mortar

Abstract

Recycled aggregates present a varied mineralogical composition and the grading of these particulates over their particle size distribution influence the aggregate properties as well as those of the composites that they form. This study proposed a comparative investigation of the influence of the particle size distribution of fine aggregates from two different origins, namely, natural crushed stone and construction and demolition waste (CDW). Three particle size distributions were defined, so that each aggregate had its fineness modulus (FM) ranked in the granulometric ranges, following the NBR 7211 Brazilian standard. The following tests were carried out: consistency, bulk density in the fresh state, compression strength, absorption (by immersion and capillarity), dimensional and mass variation. The results showed that the aggregate mineralogical composition impacted the mortar properties and that, when analyzed along with the particle size distribution, CDW showed different and varied behavior as a function of its particle size and distribution. Another finding was that mortars produced with CDW aggregate with granulometry below the lower optimal zone (FM<2.20) presented reduced mechanical and physical performance. Therefore, it was concluded that CDW aggregates should not be included in the same standards as conventional aggregates regarding the fine aggregate granulometric composition.

Engineering properties of self-compacting concrete incorporating PET fibres and recycled fine concrete aggregates

“…This reduction can be attributed to the higher water absorption capacity of RFCA in comparison to NFA, aligning with the findings of Carro-Lopez [30]. The diameter reduction may have been aggravated by the presence of a large amount of fine particles in the granulometric composition of RFCA, which showed a larger specific area, providing a larger adsorption surface [31]. Fig.…”

“…These water absorption values are associated with the nature of RFCA, characterised by a higher absorption coefficient and high porosity. Another aspect that may have influenced this result was the reduced unitary mass of this granulometric composition, indicating the presence of larger voids [31].…”

“…This increase can be attributed to the high-water absorption capacity of RFCA, and also due to the bulk density presented by the RFCA. The cement paste may have been insufficient to cover the existing spaces between the aggregates, resulting in a larger void ratio and increased absorption [31]. The capillarity absorption values for different substitutions of RFCA varied from 1.59% to 3.52% at 7 days, with 100% RFCA substitution resulting in the highest water absorption value.…”

Effects of Particle Size Distribution of Standard Sands on the Physical-Mechanical Properties of Mortars

“…Some of the properties of aggregates such as textural parameters of aggregate grains, such as grain size (expressed in terms of grain size composition), shape, surface texture, and mineralogical composition significantly affect the behavior of construction materials [ 11 , 12 , 13 , 14 , 15 , 16 ]. In addition, other aggregate factors related to the characteristics of the particle system, the number of grains in each fraction, and how these particles are organized in their equilibrium position should be considered [ 17 ].…”