Waste Glass in Cement and Geopolymer Concretes: A Review on Durability and Challenges

Abstract

Every year, the world is producing around 100 million tons of waste glass (WG), the majority of them are going to landfills that create massive environmental problems. One approach to solve this problem is to transform waste glass into construction materials. Glass is recyclable; however, the melting temperature of the glass is highly dependent on its colour that requires sorting before recycling. To overcome this challenge, many researchers and end-users are using broken glass in concrete either as a binder or aggregates. While significant investigations have done in this area, however, the outcomes of these studies are scattered, and difficult to reach a firm conclusion about the effectiveness of WG in concrete. In this study, the roles of WG and its impact on microstructural and durability properties for both cement and geopolymer concrete are critically reviewed. This review reveals that the amorphous silica in WG effectively participate to the hydration and geopolymerization process and improve concrete microstructural properties. This behaviour of WG help to produce durable concrete against shrinkage, chemical attack, freeze-thaw action, electrical and thermal insulation properties. The optimum replacement volume of binders or natural aggregates and particle size of WG need to be selected carefully to minimise the possible alkali-silica reaction. This review discusses a wide range of parameters for durability properties and challenges associated with WG concrete, which provides necessary guidelines for best practice with future research directions.

Keywords: activator; aggregate; alkali-activated cement; challenges; durability; waste glass.

Figure 1

Roles of WG in cement concrete.

Figure 2

Compressive strength of WGC with WG powder (particles < 120 µm) as SCM [41].

Figure 3

Different roles of WG and the impacts of different parameters on the performance of geopolymer concrete.

Figure 4

Microstructure and ITZ of cement mortar with WG aggregates [58].

Figure 5

SEM of geopolymers with (a) 0%, (b) 15%, and (c) 30% WG at 28 days (activated with sodium silicate modulus Ms = 1.0 and 12% Na₂O) [7].

Figure 6

Shrinkage properties of cement and geopolymers concretes with WG. (a) Drying shrinkage of concrete with WG [59]. (b) Creep strain of concrete with WG powder [42]. (c) Drying shrinkage of foamed geopolymer concretes with and without fine WG aggregate [45].

Figure 7

Durability of cement and geopolymer concretes with WG powder [73]. (a) Water penetration in WG concrete [41]. (b) Chloride penetration with varying WG contents [41]. (c) Rapid chloride migration coefficient in WG powder-based mortars [34]. (d) Expansion due to sulfate attack in slag-based geopolymer concretes with WG powder [69]. (e) Weight loss in geopolymer concretes with WG powder [73] (LS = liquid to solid ratio, N = % of activator).

Figure 8

Durability factor of WG concrete against freeze-thaw action [27].

Figure 9

Electrical conductivity of cement–WG powder paste [77].

Figure 10

Performance of glass-based cement and geopolymer concretes with varying temperatures and times [84]. (a) Variation in WG concrete temperature with varying environmental temperatures (rising) and time [83]. (b) Variation in WG concrete temperature with varying environmental temperatures (falling) and time [83]. (c) Weight loss in geopolymer concretes with varying temperature [84] [M1 with no glass, M2 with 10% and M3 is with 20% glass powder (varying curing condition)].

Figure 11

Influences of WG on the durability of concrete.

Figure 12

Environmental impact of PC and WG concrete [25].

Figure 13

Environmental impact of WG recycled cementitious mixture [91].