Fibre-Reinforced Foamed Concretes: A Review

Abstract

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.

Flexural Behaviour of Cementitious Mortars with the Addition of Basalt Fibres

“…Fibre addition is thought to overcome some of these limitations due to their beneficial influence on the mechanical properties of hardened mortar, such as impact resistance, and splitting tensile and flexural strengths [ 3 , 4 , 5 , 6 , 7 ]. Additionally, the improvement of tensile strength, flexural toughness and energy absorption capacity due to fibre addition, as far as the mechanics of cracking propagation are concerned, have been confirmed in the case of the most popular cementitious material—concrete—in numerous experimental [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ] and numerical [ 23 , 24 , 25 , 26 , 27 ] investigations. The latest research programmes in that area are focused mostly on subjects concerning newly developed materials [ 8 , 10 , 20 ], the ecological impact of building materials [ 19 , 22 ] or less typical performance tests [ 18 , 21 ].…”

Response of Novel Functionally-Graded Prepacked Aggregate Fibrous Concrete against Low Velocity Repeated Projectile Impacts

“…It is hand-actuated work and is, therefore, challenging to control. In a nutshell, adding fibres in concrete can significantly reduce the damage level of the concrete [35][36][37][38][39]. It was assumed that the top surface damaged area has an elliptical shape and the damaged shape area at the penetration depth is circular.…”

“…It is hand-actuated work and is, therefore, challenging to control. In a nutshell, adding fibres in concrete can significantly reduce the damage level of the concrete [35][36][37][38][39].…”

Combustibility of lightweight foam concrete based on natural protein foaming agent

“…Incorporation of various types of fibres can significantly improve the flexural strength (up to 4 times), tensile strength (up to 3 times), and impact strength (up to 6 times) [30].…”