Lightweight ultra-high-performance concrete (UHPC) with expanded glass aggregate: Development, characterization, and life-cycle assessment. (31st March 2023)

• Record Type: Journal Article
• Authors: Guo, Pengwei; Meng, Weina; Du, Jiang; Stevenson, Lily; Han, Baoguo; Bao, Yi
• Is Part Of: Construction & building materials. Volume 371(2023)
• Publication Date: 2023-03-31
• Subjects: Ultra-high-performance concrete (UHPC) -- Expanded glass -- Glass microsphere -- Internal curing -- Lightweight -- Polyethylene fiber; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2023.130441
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Lightweight granules and fibers are used to develop ultra-high-performance concrete. Mechanical properties and microstructure are improved while shrinkage is reduced. Life-cycle unit cost, energy consumption, and CO2 emission are highly reduced. Ductility is increased by up to 300% by using polyethylene fibers. Density is reduced to 2000 kg/m 3 while retaining a compressive strength above 125 MPa. Abstract: Ultra-high-performance concrete (UHPC) has high mechanical strengths and durability, but its density and carbon footprint are usually high. This paper developed a lightweight UHPC with low cost, low carbon footprint, low energy consumption, low thermal conductivity, and high ductility, by using three types of lightweight ingredients: hollow glass microsphere (460 kg/m 3 ), expanded glass aggregate (800 kg/m 3 ), and polyethylene fibers (970 kg/m 3 ). Underlying mechanisms were investigated through thermogravimetry, X-ray diffraction, and mercury intrusion porosimetry analyses. Results showed that the hollow glass microsphere reduced the thermal conductivity of concrete; the expanded glass aggregate mitigated shrinkage while enhancing compressive strengths and flexural properties of concrete through internal curing; and the polyethylene fibers promoted multiple cracks, increasing ductility and toughness of concrete. With 20 % hollow glass microsphere, 1.5 % polyethylene fiber, and 25 % expanded glass, UHPC mixtures were developed to achieve high compressive strength (>127 MPa) and high flexural strength (>21 MPa), while reducing the density by 20 % and carbon footprint by 16 % as well as embodied energy by 27 %.