Improving the flexural capacity of extrudable foamed concrete with glass-fiber bi-directional grid reinforcement: An experimental study

Falliano, Devid; Domenico, Dario De; Ricciardi, Giuseppe; Gugliandolo, Enrico

doi:10.1016/j.compstruct.2018.10.092

Cited by 81 publications

(34 citation statements)

References 28 publications

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“…In the previously listed studies, these fibres were introduced in an amount of 0.2–1.5% volume of the concrete mixture; however, in this article, the fibre content ranges upper limit has been extended to 5%. As an alternative to traditional reinforcement, one strategy with composite mesh and mesh combined with fibre has also been studied for lightweight foamed concrete (LWFC) [ 23 , 36 , 37 , 38 ]…”

Section: Introductionmentioning

confidence: 99%

Fibre-Reinforced Foamed Concretes: A Review

et al. 2020

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Foamed concrete (FC) is a high-quality building material with densities from 300 to 1850 kg/m3, which can have potential use in civil engineering, both as insulation from heat and sound, and for load-bearing structures. However, due to the nature of the cement material and its high porosity, FC is very weak in withstanding tensile loads; therefore, it often cracks in a plastic state, during shrinkage while drying, and also in a solid state. This paper is the first comprehensive review of the use of man-made and natural fibres to produce fibre-reinforced foamed concrete (FRFC). For this purpose, various foaming agents, fibres and other components that can serve as a basis for FRFC are reviewed and discussed in detail. Several factors have been found to affect the mechanical properties of FRFC, namely: fresh and hardened densities, particle size distribution, percentage of pozzolanic material used and volume of chemical foam agent. It was found that the rheological properties of the FRFC mix are influenced by the properties of both fibres and foam; therefore, it is necessary to apply an additional dosage of a foam agent to enhance the adhesion and cohesion between the foam agent and the cementitious filler in comparison with materials without fibres. Various types of fibres allow the reduction of by autogenous shrinkage a factor of 1.2–1.8 and drying shrinkage by a factor of 1.3–1.8. Incorporation of fibres leads to only a slight increase in the compressive strength of foamed concrete; however, it can significantly improve the flexural strength (up to 4 times), tensile strength (up to 3 times) and impact strength (up to 6 times). At the same time, the addition of fibres leads to practically no change in the heat and sound insulation characteristics of foamed concrete and this is basically depended on the type of fibres used such as Nylon and aramid fibres. Thus, FRFC having the presented set of properties has applications in various areas of construction, both in the construction of load-bearing and enclosing structures.

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Section: Introductionmentioning

confidence: 99%

Fibre-Reinforced Foamed Concretes: A Review

et al. 2020

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“…Sometimes fine sand, fly ash, superplasticizer, fibers, or silica fume are used as well [17]. Falliano et al used directional composite grid reinforcement to improve the mechanical properties of foamed concrete [18]. For a given dry density, foamed concrete prepared using fly ash as a filler has better mechanical properties than the equivalent sand-based foamed concrete [19].…”

Section: Introductionmentioning

confidence: 99%

Preparation and Characterization of Ultra-Lightweight Foamed Concrete Incorporating Lightweight Aggregates

et al. 2019

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Increasing interest is nowadays being paid to improving the thermal insulation of buildings in order to save energy and reduce ecological problems. Foamed concrete has unique characteristics and considerable potential as a promising material in construction applications. It is produced with a wide range of dry densities, between 600 and 1600 kg/m3. However, at a low density below 500 kg/m3, it tends to be unstable in its fresh state while exhibiting high drying shrinkage in its hardened state. In this study, lightweight aggregate-foamed concrete mixtures were prepared by the addition of preformed foam to a cement paste and aggregate. The focus of the research is the influence of fly ash, as well as fine lightweight aggregate addition, on the properties of foamed concrete with a density lower than 500 kg/m3. Concrete properties, including stability and consistency in the fresh state as well as thermal conductivity and mechanical properties in the hardened state, were evaluated in this study. Scanning electron microscopy (SEM) was used to study the microstructure of the foamed concrete. Several mixes with the same density were prepared and tested. The experimental results showed that under the same bulk density, incorporation of fine lightweight aggregate has a significant role on compressive strength development, depending on the characteristics of the lightweight aggregate. However, thermal conductivity is primarily related to the dry density of foamed concrete and only secondarily related to the aggregate content. In addition, the use of fine lightweight aggregate significantly reduces the drying shrinkage of foamed concrete. The results achieved in this work indicate the important role of lightweight aggregate on the stability of low-density foamed concrete, in both fresh and hardened states.

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“…Similar to other cementitious materials, in the low-density range foamed concrete has poor mechanical strength. For this reason, different strategies have been proposed in the relevant literature to improve the mechanical strength of foamed concrete at low densities and to limit its brittle behavior, such as addition of fly ash and silica fume [5], introduction of short fibers of different nature [6]- [9] or placement of bi-directional grid reinforcement [10], [11]. Regardless of the reinforcement adopted, the mechanical characteristics of such lightweight cementitious materials is affected by the mix design (water-to-cement ratio, quality and characteristics of the aggregates, etc.)…”

Section: Introductionmentioning

confidence: 99%

“…The choice of the use of biochar derives from previous studies that have shown significant increases in terms of both flexural strength and fracture energy of traditional cement-based composite materials [24]. Moreover, the foamed concrete of this experimental campaign is prepared with a viscosity enhancing agent (VEA) such that the resulting mix has high cohesion and viscosity at the fresh state (green strength), and is termed "extrudable foamed concrete" [2], [10], [25]. As a first step of this experimental campaign, standardized prismatic specimens were prepared and tested according to UNI EN 196-1, in order to determine the optimal process to introduce the biochar particles into the foamed concrete matrix (among three possibilities: mixed with cement, dispersed into the hydration water or dispersed in the pre-formed foam).…”

Section: Introductionmentioning

confidence: 99%

Influence of biochar additions on the fracture behavior of foamed concrete

Falliano

Domenico

Sciarrone

et al. 2019

Frattura Ed Integrità Strutturale

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The present study concerns the experimental investigation of foamed concretes with 1600 kg/m 3 density that incorporate biochar additions in the mix. A series of small notched beams are prepared to determine the fracture energy in CMOD (crack mouth opening displacement) mode and the mechanical properties in terms of flexural and compressive strength. Besides the evaluation of such properties for classical foamed concrete, the influence of the addition of biochar in the lightweight cementitious paste is comparatively investigated. Two different concentrations of biochar are analyzed, namely 2% and 4% of the cement weight, and two different curing conditions are studied, namely in air and in water at controlled temperature for 28 days. The results demonstrate that better fracture behavior are obtained with 2% biochar and air curing conditions. The biochar additions in moderate concentrations (e.g. 2%) seems to make the fracture surface more tortuous, thus justifying the numerical outcomes, and does not impair the flexural strength. Further microstructural investigation is underway to confirm the experimental observations. This research paves the way for a promising construction material that is more environmentally friendly and sustainable than traditional materials used in the building industry.

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Improving the flexural capacity of extrudable foamed concrete with glass-fiber bi-directional grid reinforcement: An experimental study

Cited by 81 publications

References 28 publications

Fibre-Reinforced Foamed Concretes: A Review

Fibre-Reinforced Foamed Concretes: A Review

Preparation and Characterization of Ultra-Lightweight Foamed Concrete Incorporating Lightweight Aggregates

Influence of biochar additions on the fracture behavior of foamed concrete

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