Development of ultra-high-performance geopolymer concrete

Abstract

This paper presents the development of ambient temperature cured ultra-high-performance geopolymer concrete (UHPGPC). Ultra-high-performance concrete (UHPC) mixtures were developed by completely eliminating Portland cement and activating industrial by-product materials such as ground granulated blastfurnace slag and silica fume.Local standard sand (maximum size 2 mm), quartz sand (600 ìm) and 0 . 16 mm diameter steel fibres of 13 and 6 mm length were used. Fresh properties (density and flowability) and mechanical properties (compressive strength) of the UHPGPC produced under ambient temperature curing conditions were evaluated. Four mixtures with fibres and one mix without fibre addition were studied as the UHPGPC mixtures. The highest average compressive strengths obtained were 175 MPa for UHPGPC with steel fibres (1% 6 mm and 2% 13 mm) and 124 MPa for UHPGPC without fibres. Prismatic specimens (100 3 100 3 500 mm) were cast to determine the flexural strength, which was found to be 10 . 3-13 . 5 MPa and 9 . 1 MPa for mixes with and without steel fibres respectively. The compressive and flexural strengths obtained in this work are comparable to UHPC strengths presented in the literature. Production of this innovative material with industrial by-products and without the conventional curing regimes used for UHPC will improve sustainability and lead to cast-in-situ applications of UHPC.

Microstructure and compressive properties of silicon carbide reinforced geopolymer

“…One can see that in our work, the optimized process and concentration of GP/SiC p , led to a significant improvement of compressive strength (~155 MPa) which is comparable to that of the steel fiber reinforced geopolymer [35]. This value is close to the level of human bone [28] and reaches the level of superhigh strength concrete [27].…”

“…With incorporation of 1 wt.% of graphene nanoplatelets, the compressive strength of fly ash based geopolymer increased from 32 MPa to 46 MPa [32]. In addition, various types of fibers, such as polyvinyl alcohol (PVA) fibres [33,34], steel fibers [35,36], cotton fibres [37], and polypropylene (PP) fibres [36,38], were used to improve the mechanical properties of geopolymers, especially the compressive properties. For instance, the compressive strength of a geopolymer reinforced with 2 vol.% of PVA fibers reached 63.7 MPa with an increase of ~17% [34].…”

“…For instance, the compressive strength of a geopolymer reinforced with 2 vol.% of PVA fibers reached 63.7 MPa with an increase of ~17% [34]. A high compressive strength of geopolymer concrete (~175 MPa) was obtained with an addition of 13 mm steel fibers [35]. For cotton fabric reinforced geopolymer composites, an increase of 350% in compressive strength was accomplished by orienting 8.3 wt.% cotton fabric along the loading direction [37].…”

A state of the art review into the use of geopolymer cement for road applications

“…Compressive strengths of at least 60 MPa at 60 minutes, when cured at 80 • C, were reported. This was followed by the development of ultra-highperformance geopolymer cement by Ambily et al (2014). This cement was based on a slag and silica fume mix.…”

Influence of curing regime and steel fibres on the mechanical properties of UHPC

“…The literature reveals that the observed compressive strength of UHPC samples is dependent on the hydration of cement, pozzolanic reactions of silica fume at lower temperatures and the combined action of silica fume and quartz at higher temperatures (Zheng et al, 2014). Accelerated curing is needed for proper development of the microstructure of calcium silicate hydrates (Ambily et al, 2013;Cheyrezy et al, 1995;Habel et al, 2006;Prem et al, 2013;Wille et al, 2012). To examine the effect of curing on UHPC samples, compression tests and microstructural studies were carried out on specimens cured with water, steam and heat.…”