Engineering performance of reinforced lightweight geopolymer concrete beams produced by ambient curing

Abstract

The use of lightweight concrete can provide specific advantages that are favoring for mitigating seismic risk in building design. On the other hand, a significant reduction of carbon footprint could be possible through the use of geopolymer concrete. However, geopolymer concrete is mostly assessed through small specimens without reinforcement elements. This paper aims to couple the advantage of lightweight mixtures and ambient-cured geopolymerization in reinforced beams. To do this, engineering performance of reinforced lightweight geopolymer concrete was extensively investigated with different aspects. In mixtures, pumice and volcanic tuff aggregates were used with an appropriate gradation. Flexural strength, deflection capacities, initial stiffness, ductility, and energy dissipation capacity of reinforced geopolymer beams were investigated with the proposed configuration. Compressive strength and unit weight of the developed mixtures were also evaluated to meet design requirements for lightweight concrete. Results indicated that certain engineering properties (energy dissipation capacity and initial stiffness) of developed lightweight geopolymer concrete were considerably comparable with lightweight Portland cement-based concrete. Although compressive strength and unit weight of the developed geopolymer mixtures were satisfying, microstructural analysis indicated a weak bonding behavior between paste and lightweight aggregates.

Mechanical, light transmittance properties and simulation study of sustainable translucent lightweight aggregate concrete

“…The cement used in this experimental study is P•O 42.5 Portland cement (OPC) complied with GB 175-2007, the river sand (RS) from Huludao, Liaoning is used as fine aggregate. Moreover, shale pottery (SP) is used to replace RS in the preparation of self-compacting lightweight aggregate mortar, and the substitution ratio was 30% [23,24]. The chemical compositions of OPC and SP are listed in table 1.…”

Influence of fiber characteristics on sulfate resistance of ambient‐cured geopolymer concrete

“…28,29 Due to the economic and environmental concerns mentioned above, production of sustainable alternative binders to PC has gained considerable attention. 4,30,31 Geopolymers, also called alkali activated binders, are new generation binder types that stand out among the searches for green alternatives binders. 7,9,32,33 Geopolymer binders are semi crystal inorganic polymers synthesized by geopolymerization reactions between highly alkaline solutions (sodium hydroxide and sodium silicate) and aluminosilicate precursors (natural or waste pozzolans).…”

“…Due to the economic and environmental concerns mentioned above, production of sustainable alternative binders to PC has gained considerable attention 4,30,31 . Geopolymers, also called alkali activated binders, are new generation binder types that stand out among the searches for green alternatives binders 7,9,32,33 .…”

Effects of replacement ratio and particle size distribution of recycled coarse aggregate on mechanical properties of concrete designed using equivalent mortar volume method

“…In this manner, several technical ways have been proposed to reduce the cement content in recycled concrete. [14][15][16] Conceptually, the equivalent mortar volume (EMV) mixing method has been recently proposed to produce RAC with less new mortar, saving binding materials (by 15.6%-48.4%) and natural fine aggregate (NFA) (by 15.6%-71.3%). 17,18 In addition to the natural-material-saving advantages, the mechanical properties of the EMV RAC could be comparable to that of the reference NAC, 18,19 increasing its potential structural applications.…”

“…In the area of the environmental assessment of concrete, cement production is by far the largest contributor to all impacts. In this manner, several technical ways have been proposed to reduce the cement content in recycled concrete 14–16 . Conceptually, the equivalent mortar volume (EMV) mixing method has been recently proposed to produce RAC with less new mortar, saving binding materials (by 15.6%–48.4%) and natural fine aggregate (NFA) (by 15.6%–71.3%) 17,18 .…”