Development of strain‐hardening lightweight engineered cementitious composites using hollow glass microspheres

Abstract

Hollow glass microsphere (HGM) is a kind of ultra-lightweight inorganic nonmetallic material with hollow structure, and it is a versatile and high-performance new lightweight material developed in recent years. HGMs comprising at least 45 wt% of recycled glass based on the total weight of a feed composition from which the hollow microspheres are derived. The purpose of this study is to develop high-performance lightweight engineered cementitious composites (LWECCs) using efficiently waste recycled HGMs as a lightweight filler substitute for sustainable construction. LWECC is a flowable type of lightweight fiber-reinforced concrete, which is able to illustrate strain-hardening behaviors rather than tension softening after an initial crack and possesses a tensile strain up to 6%; however, available lightweight fillers in LWECC exhibit more brittle behavior compared with normal weight engineered cementitious composite. In this study, three different types of HGMs are used as lightweight fillers with 0.25, 0.40, and 0.60 g/cm 3 densities, and their effects on fresh and mechanical properties of LWECC have been investigated. HGMs fillers are replaced at 40 and 60% weight of fly ash in the control mix. To evaluate the strength of the LWECC, samples were cured for periods of 7 and 28 days and then tested for mechanical properties by compression test and three-point bending. Furthermore, the scanning electron microscopy, energy dispersive X-ray spectroscopy and morphological observations to confirm the dispersion of the lightweight filler have been captured. K E Y W O R D S

Pozzolanic activity quantification of hollow glass microspheres

“…HGMS were also studied as addition for engineered cementitious composites [7][8][9][10]. Composites were designed with fly ash, silica fume, polyvinyl alcohol fibres and HGMS.…”

“…% of fly ash replacements, the lightweight composite with the HGMS of higher crush strength yielded the higher compressive strength. Additionally, coated HGMS were used as fly ash replacement [7]. Within SEM and EDS analysis a chemical and physical interaction between coated HGMS and cement hydration products was observed.…”

Evaluation of mechanical and microstructure properties of engineered cementitious composites made of zeolite

“…5 The lightweight concrete ECC (LW-ECC) is designed and used for sites in which minimal dead loads are required. 6,7 The green engineered cement composite (G-ECC) is also designed to minimize the structural weights and maximize the infrastructure sustainability. 8 As previously noted, one of the most important features of ECC is its high tensile ductility.…”

Feasibility of Using the Hollow Glass Microsphere to Develop Lightweight CAC-GGBFS-Blended Strain-Hardening Cementitious Composites

“…A common method for producing lightweight SHCC is to incorporate lightweight aggregates. A lightweight environmentalfriendly filler material, hollow glass microsphere (HGM), has been widely used as a filler material for sand replacement in cement-based composites (Wang et al, 2019;Al-Gemeel et al, 2018;Aslani and Wang 2019). HGM is a dimension-controlled hollow spherical shape particle with air encapsulated by a thin glass enclosure of sphere.…”

“…The HGM material is widely available with a bulk density ranging from 120 kg/m 3 to 490 kg/m 3 and the particle size is about 81 µm and less. Compared to the popular lightweight fly ash cenosphere materials, the use of HGM can offer a lower density and improve the greenness of the cementitious composite as it contains a significant amount of recycled glass (Wang et al, 2019;Meddah, 2019;Aslani et al, 2021). Hence, by replacing silica aggregates with HGM, an SHCC with more sustainable effect can be produced.…”