Glass Fiber Reinforced Concrete Research Articles

Effects of Barite Sand Addition on Glass Fiber Reinforced Concrete Mechanical Behavior

Glass fiber reinforced concrete (GFRC) is a cementitious composite reinforced by the addition of alkali-resistant glass fibers. GFRC is widely used for various types of precast products in civil engineering industries. GRFC mixes generally include silica sand to produce precast concrete elements; however, silica sand was replaced with barite sand at the ratios of 5%, 10 % and 15 % of wt. in order to reveal its applicability and potential for different engineering purposes. The flexural strength and the freeze-thaw(F&T) resistance of the composites were studied. The experimental results showed that the replacement of silica sand with barite sand up to 15 % of wt. enhances the mechanical properties of the composites in respect to flexural strength and F&T resistance properties.

Comparative Study of Sisal Fibre and Glass Fibre Reinforced Concrete -A Review

Comparative Study of Sisal Fibre and Glass Fibre Reinforced Concrete -A Review

Development of deflection hardening cementitious composites using glass fibres for flexural repairing/strengthening concrete beams: experimental and numerical studies

This paper presents experimental and numerical programmes employed to strengthen concrete beams using glass fibre-reinforced concrete in order to achieve deflection hardening behaviour. Numerous tests were carried out on 270 specimens in the experimental phase in order to characterise mechanical properties of beams reinforced with glass fibre. Three beams were then cast with plain concrete and experimentally tested under flexural load conditions. Based on the experimental results, numerical simulations were conducted and the results were calibrated to the experimental results. Then, the robust-able FE models were used to strengthen concrete beams through numerical simulations. Furthermore, section enlargement method was also used to strengthen the concrete beams. The experimental and numerical results showed that using glass fibre-reinforced concrete layer to strengthen the concrete beams through the section enlargement method significantly improves the load carrying capacity and ultimate deflection.

Advancing the manufacture of complex geometry GFRC for today's building envelopes

Advancing the manufacture of complex geometry GFRC for today's building envelopes

Advancing the manufacture of complex geometry GFRC for today's building envelopes

Advancing the manufacture of complex geometry GFRC for today's building envelopes

Introduction to state‑of‑the‑art thin-walled GFRC

Thin-walled fibre reinforced concrete (FRC) elements are being adapted for large scale buildings with complex geometry envelopes. The current production methods, developed in the initial stages of glass fibre reinforced concrete (GFRC) elements in the 1970s, are limited when striving to produce more complex shaped FRC elements. The limitations of the FRC elements in terms of material properties and surface quality are described for these current state of the art production methods. New production methods and casting techniques are proposed that will advance the application of thin-walled FRC for buildings with complex geometry envelopes. Evaluation of the current state of the art production methods concluded that the sprayed GFRC methods are currently the most flexible solution which has the greatest potential for adapting the method to the requirements of complex geometry buildings. Further development of thin-walled GFRC elements would be possible by developing a mould system for complex geometry panels with an edge-return, which can utilise glass fibre reinforced ultra high performance concrete (GF-UHPC) with a vacuum technology, it would be possible to produce complex geometry GFRC elements with an increased material performance and yet still meet the aesthetic requirements of minimal visual defects in the surface of thin-walled elements.

Key problems associated with complex geometry GFRC

Glass fibre reinforced concrete (GFRC) elements have become a sought after cladding material since their introduction as rain screen cladding for buildings. To advance GFRC for a range of complex geometry building envelopes this also requires advances in existing moulding techniques for thin-walled GFRC elements. To do so it is necessary to define the current state of thin-walled GFRC elements and the constraints and limits placed on them by existing production techniques. This paper identifies the current architectural and aesthetic requirements of thin-walled GFRC elements and maps their range of complexity, from 1-D to 3-D, to the limits of the most appropriate production method. This will inform guidelines for the future design development of thin-walled GFRC and enable an innovative approach to further advance the moulding techniques for thin-walled GFRC elements for a variety of complex geometry building envelopes. The paper concludes on which further steps need to be taken to advance thin-walled glass fibre reinforced concrete for tomorrow’s architectural buildings envelopes with complex geometries.

Effect of Applying Techniques and Polymer Content on Strength and Drying Shrinkage of Glass Fiber Reinforced Concrete

The purposes of this study were to evaluate compressive strength, flexural strength, and drying shrinkage of Glass Fiber Reinforced Concrete (GFRC) applying different techniques and varying polymer content. Two groups of specimens were classified applying the techniques: sprayed and premixed methods. AR-Glass was used with fiber content of 3 to 4% by volume. GFRC was mixed and applied different techniques with proportions of Styrene Butadiene Rubber (SBR) content of 0%, 3%, 6%, and 9% by weight of cement. Compressive and flexural strength tests were performed at 1 and 28 days. Drying shrinkage tests were measured up to 98 days. The results obtained showed that increasing the SBR content showed a lower compressive strength of GFRC for both sprayed and premixed techniques. In the other hand, 28-day flexural strength results of GFRC for both premixed and sprayed techniques were found to increase with increasing SBR content. The GFRC mixes using sprayed technique exhibited flexural strength higher than the corresponding mixes using premixed technique because of the two-dimensional layer of fiber alignment for the sprayed technique. Increasing the SBR content exhibited the lower drying shrinkage of GFRC. At the age of 98 days, the drying shrinkage of GFRC using 9% SBR content was about 40% lower than that of GFRC using 0% SBR content.

Developing a solution for the premixed concrete method and proposing a step by step fabrication process.

Complex geometry concrete is being used in building and infrastructure projects however, costly in-situ mouldings are necessary to achieve these geometries. Advancing discretised concrete shell structures requires the development of a new moulding system at lower cost and reduced mould production times. Future thinwalled glass fibre reinforced concrete (GFRC) elements must possess good continuous surface quality, with the required edge-returns and panel offsets, combined with the physical material properties to increase spans and lower the risk of visible surface cracks. Existing moulding systems do not have the capability to meet these contemporary architectural aesthetic and design aspirations. A new mould system to produce free-form thin-walled GFRC elements is presented and can be used to replace CNC milled moulds for the manufacture of thin walled GFRC. Such a system allows the mould for thin-walled GFRC elements to be produced in a fast, cost effective and more efficient manner. A new step-by-step process to achieve such new thin-walled GFRC panels is described, permitting the fabrication of complex geometry thinwalled GFRC elements using more cost effective large-scale production methods. This process bridges the gap between the limited capabilities of current solutions, and the architectural aesthetic demands for good surface quality, with the option of having an edge-return and the same surface quality as the front surface to give a monolithic appearance.

Developing a solution for the sprayed concrete method and proposing automated process.

Resolving the challenges of advancing thin-walled glass fibre reinforced concrete (GFRC) requires a novel, more automated digital design and manufacturing process that meets the requirements of present demands for thin-walled GFRC panels. The design, optimisation and manufacture of moulds using existing approaches is subject to many limitations and constraints that result in feedback loops between each stage of the design and manufacturing processes. This precludes the efficient and fully automated digital design and manufacture of complex geometry thin-walled GFRC panels. The proposed mould system overcomes many of these constraints, and when combined with new software plug-ins, will be capable of digitally resolving the limitations or constraints that interrupt each key stage of the design and manufacturing processes. These plug-ins have been characterized to provide a seamless interface between software and hardware with minimal delays caused by design feedback loops to allow a fully automated digital design process to be realised. The impact of the new mould on this novel process is analysed and further research necessary to advance the process is identified.

Seismic vulnerability assessment of strengthened Glass Fiber Reinforced Concrete (GFRC)

This paper presents the effect of using Carbon Fiber Reinforced Polymers (CFRP) as retrofitting material on seismic behavior of Plain Cement Concrete (PCC) and Glass Fiber Reinforced Concrete (GFRC). The experimental work was carried out in two steps. In first step, cylindrical specimens of size 150 mm × 300 mm were cast by using both PCC and GFRC. In second step, the specimens were wrapped by CFRP in three different patterns. All the specimens were tested under monotonic compressive loading. The test results were later used in the non-linear static cyclic analysis of reinforced concrete frame modeled in a finite element based analytical tool. Seismic vulnerability assessment was then carried out using a modified capacity spectrum method to develop analytical curves for the frames. The results showed significant improvement in seismic performance of frames strengthened by CFRP. Collapse hazard level for unconfined GFRC structure was increased by 20.73% as compared to unconfined PCC structure. There was 21 to 28% improvement observed in collapse hazard level in confined PCC structures as compared to their unconfined counterparts. However, confinement of GFRC structures resulted in only 8% increase in collapse hazard level as compared to unconfined GFRC structures.

Use of glass and nylon fibers in concrete for controlling early age micro cracking in bridge decks

One of the major defects in concrete bridge decks are the formation of early age micro cracking which ultimately reduces its durability. The inclusion of fibers in concrete slabs has showed satisfactory performance with improved mechanical properties and reduced early age micro cracking (EAMC). The relative high compressive strength (CS), achieved by using high cement content, is the main cause of early age micro cracking in concrete. The low tensile strength (TS) also results in less resistance to early age cracking. Other factors causing EAMC include temperature rise, water content and shrinkage strain. The EAMC can be reduced by increasing CS and TS with use of economical materials other than cement. In this work, mechanical properties of glass fiber reinforced concrete (GFRC) and nylon fiber reinforced concrete (NFRC) are determined for the application of concrete bridge decks. The effectiveness of glass fibers (GF) and nylon fibers (NF) in concrete will be checked by comparing mechanical properties of GFRC and NFRC with that of plain concrete (PC). The mix design ratio of PC is 1:3.33:1.67 (cement:sand:aggregate) with a water cement ratio of 0.71. The GF and NF having a length of 50mm and a fiber content of 5%, by mass of cement, are added in the concrete mixture for the production of GFRC and NFRC. Standard specimens are tested for determining compressive, splitting-tensile and flexural strengths of PC, GFRC and NFRC. Pre-crack energy absorption and toughness indices are also studied for different types of loadings i.e. compressive, splitting-tensile and flexural loadings. There is a decrease in compressive strength and an increase in splitting-tensile and flexural strengths of GFRC and NFRC compared to that of PC. Even though pre-crack energy absorption of GFRC and NFRC is less but their toughness indices are more than that of PC. Thus, GFRC and NFRC are suitable for reducing EAMC in bridge decks.

A new method to advance complex geometry thin-walled glass fibre reinforced concrete elements

Complex geometry concrete is being used in building and infrastructure projects, however costly in-situ mouldings are necessary to achieve these geometries. Advancing discretised concrete shell structures requires the development of a new moulding system at lower cost and reduced mould production times. Future thin-walled glass fibre reinforced concrete (GFRC) elements must possess good surface quality, with the required edge returns and offsets, combined with the physical material properties to increase spans and lower the risk of visible surface cracks. Existing moulding systems do not have the capability to meet these contemporary architectural aesthetic and design aspirations. A new mould system to produce freeform thin-walled GFRC elements is presented and can be used to replace CNC milled moulds for the manufacture of thin walled GFRC. Such a system allows the mould for thin-walled GFRC elements to be produced in a fast, cost effective and more efficient manner. A step-by-step process to achieve such thin-walled GFRC panels is described permitting the fabrication of complex geometry thin-walled GFRC elements using more cost effective large-scale production methods. This process bridges the gap between the limited capabilities of current solutions and the architectural aesthetic demands for good surface quality, with the option of having an edge-return of the same surface quality as the front surface to give a monolithic appearance.

Effects of basalt and glass chopped fibers addition on fracture energy and mechanical properties of ordinary concrete: CMOD measurement

This study investigates fracture behavior of basalt fiber reinforced concrete (BFRC) and glass fiber reinforced concrete (GFRC) comparatively. For this purpose, three-point bending tests were carried out on notched beams produced using BFRC and GFRC with 0.5, 1, 2 and 3kg/m3 fiber contents to determine the value of fracture energy. Fracture energies of the notched beam specimens were calculated by analyzing load versus crack mouth opining displacement (CMOD) curves by the help of RILEM proposal. In addition, microstructural analysis of the three components; cement paste, aggregate, basalt and glass fiber were performed based on the Scanning Electron Microscopy and Energy-Dispersive X-ray Spectroscopy examinations and analysis were discussed. The results showed that the effects of the fiber contents on fracture energy were very significant. The splitting tensile and flexural strength of BFRC and GFRC were improved with increasing fiber content whereas a slight drop in flexural strength was observed for high volume of fiber content. On the other hand, effect of fiber addition on the compressive strength and modulus of elasticity of the mixtures was insignificant.

Mechanical Properties of Glass Fiber Reinforced Concrete (GFRC)

Mechanical Properties of Glass Fiber Reinforced Concrete (GFRC)

The impact of a new mould system as part of a novel manufacturing process for complex geometry thin-walled GFRC

ABSTRACTResolving the challenges of advancing thin-walled glass fibre-reinforced concrete (GFRC) requires a novel, more automated digital design and manufacturing process that meets the requirements of present demands for thin-walled GFRC panels. The design, optimisation and manufacture of moulds using existing approaches are subject to many limitations and constraints that result in feedback loops between each stage of the design and manufacturing processes. This precludes the efficient and fully automated digital design and manufacture of complex geometry thin-walled GFRC panels. The proposed mould system described in this article overcomes many of these constraints and, when combined with new software plug-ins, will be capable of digitally resolving the limitations or constraints that interrupt each key stage of the design and manufacturing processes. These plug-ins have been characterised to provide a seamless interface between software and hardware with minimal delays caused by design feedback loops to allow a fully automated digital design process to be realised. The impact of the new mould on this novel process is analysed and further research necessary to advance the process is identified.

Experimental Study on Glass Fibre Reinforced Concrete with Partial Replacement of Copper Slag by Fine Aggregate

Experimental Study on Glass Fibre Reinforced Concrete with Partial Replacement of Copper Slag by Fine Aggregate

Glass Fibre Reinforced Concrete Products for Construction Industry and Architecture

Glass fibre reinforced concrete is a material which found its undisputable place in architecture and construction industry. Architecture has been using its creativity potential at building atypical elements of a specific building and the needed detail. This specific material enables unusual geometrical shapes, curves and surfaces. It is able to create custom-made original works. It is not a material which is used to make the products competitive with their price and serial production etc. It wants to be original, offers new challenges and provide new forms of its application to the people. The paper describes selected glass fibre reinforced concrete products which can serve as examples of new components creation to the producers and architects.

Mechanical properties and fracture behavior of basalt and glass fiber reinforced concrete: An experimental study

Basalt fiber (BF) is a novel kind of inorganic fiber which is manufactured from the extrusion of melted basalt rock and is commercially available. This study comparatively analyze the application of basalt and glass fibers as fiber reinforcement in high strength concrete. It was observed from the test results that there was no significant effect of fiber inclusion on the compressive strength and modulus of elasticity of concrete. The splitting tensile strength of basalt fiber reinforced concrete (BFRC) increased with increasing fiber dosage whereas there was no increase in strength for glass fiber reinforced concrete (GFRC) was observed beyond 0.50% fiber dosage. In a trend similar to splitting tensile strength, the flexural strength of BFRC increased with increasing fiber content in a gradual fashion but no such change was observed for GFRC after 0.50% fiber content. Fracture energy increased significantly after 0.25% dosage for both basalt and glass reinforced concrete. The KIC and CTODC results of the BFRC showed that BF inclusion improves the performance of concrete more when compared to GF with respect to crack resistance and ductility.

An innovative approach to manufacture thin-walled glass fibre reinforced concrete for tomorrow's architectural buildings envelopes with complex geometries

Glass fibre reinforced concrete (GFRC) elements have become a sought after cladding material since their introduction as rain screen cladding for buildings. To advance GFRC for a range of complex geometry building envelopes this also requires advances in existing moulding techniques for thin-walled GFRC elements. To do so it is necessary to define the current state of thin-walled GFRC elements and the constraints and limits placed on them by existing production techniques. This paper identifies the current architectural and aesthetic requirements of thin-walled GFRC elements and maps their range of complexity, from 1-D to 3-D, to the limits of the most appropriate production method. This will inform guidelines for the future design development of thin-walled GFRC and enable an innovative approach to further advance the moulding techniques for thin walled GFRC elements for a variety of complex geometry building envelopes. The paper concludes on which further steps need to be taken to advance thin-walled glass fibre reinforced concrete for tomorrow's architectural buildings envelopes with complex geometries.