Improving the Performance of Structural Members by Incorporating Incinerated Bio-Medical Waste Ash in Reinforced Geopolymer Concrete

This study aims to analyze the use of Incinerated Bio-Medical Waste Ash (IBWA) in reinforced concrete structural member with ground granulated blast furnace slag (GGBS) as an alternate building ingredient instead of cement. Biomedical waste was produced from various medical resources such as hospitals, medical institutes and research centres. GGBS is the waste generated from the steel plant. The climate is now being affected by the release of CO2 (global warming) from the Portland cement industries. Therefore, greater attention must be paid to study efforts to use geopolymer concrete. Geopolymer is a novel inorganic eco-friendly binding agent derived from an alkaline solution that stimulates aluminosilicate source material (GGBS, Rice Husk Ash, Quartz Powder, metakaolin, fly ash and Silica Fume). In this research, laboratory tests for Reinforced Geopolymer Concrete (RGPC) beams (deflection, ductility factor, flexural strength and toughness index) and columns (load-carrying ability, stress-strain behaviour and load-deflection behaviour) were conducted for three types of proportions using [30% IBWA – 70% GGBS Geopolymer concrete, GGBS Geopolymer concrete and Reinforced Cement Concrete. The experimental findings revealed that the performance of reinforced 30% IBWA – 70% GGBS geo-polymer beams and columns worked more effectively than reinforced cement concrete beams and columns.

Kenaf Fibre Reinforced Cementitious Composites

Increased environmental awareness and the demand for sustainable materials have promoted the use of more renewable and eco-friendly resources like natural fibre as reinforcement in the building industry. Among various types of natural fibres, kenaf has been widely planted in the past few years, however, it hasn’t been extensively used as a construction material. Kenaf bast fibre is a high tensile strength fibre, lightweight and cost-effective, offering a potential alternative for reinforcement in construction applications. To encourage its use, it’s essential to understand how kenaf fibre’s properties affect the performance of cement-based composites. Hence, the effects of KF on the properties of cementitious composites in the fresh and hardened states have been discussed. The current state-of-art of Kenaf Fibre Reinforced Cement Composite (KFRCC) and its different applications are presented for the reader to explore. This review confirmed the improvement of tensile and flexural strengths of cementitious composites with the inclusion of the appropriate content and length of kenaf fibres. However, more studies are necessary to understand the overall impact of kenaf fibres on the compressive strength and durability properties of cementitious composites.

Empirical equation and experimental validation of shear parameters for high strength concrete (HSC)

With many benefits of the high strength concrete (HSC) the more brittle behaviour that leads to sudden failure makes it important for proper understanding of its behaviour and safe and efficient estimation of capacities. Research on the behaviour of HSC has been extensively carried out since last decade. HSC has higher tensile strength hence a higher cracking shear can be expected. This paper analyzes the different international standards available for estimating concrete’s component of shear strength for reinforced cement concrete (RCC) beam. Different important factors mainly strength in compression, steel reinforcement (dowel action), ratio of shear span and depth, size effect i.e. depth along with the aggregate type (density of concrete) contributing to shear stress (Tc) of concrete has been also analyzed and thereafter, an equation has been proposed to compute or predict Tc value for concrete of both normal and higher grade or strength. The proposed equation has been validated by experimental results wherein 12 RCC beams (with and without reinforcement for shear) were cast and tested to fail in shear. The experimental results validated the proposed equation with considerable factor of safety keeping in view the sudden and brittle nature of failure in concrete in case of shear.

FRP for Marine Application

Fiber Reinforced Plastics (FRPs) are widely used in marine sector owing to their high specific strength and resistance to marine corrosion. For naval application, additional advantages are transparency to radar wave and better vibration damping than metals. The use of various FRPs in off-shore structures and marine vessels needs analysis of desired properties considering the types of matrices and fiber. The common consideration is effect of sea water on the properties of the FRP. This chapter gives a brief on use of different FRPs in various areas such as off-shore pillars, Reinforced Cement Concrete (RCC) enclosers, primary and secondary marine components. A brief discussion is included here on diffusion models and estimation of durability by a time-temperature superposition principle applied to water ingress and corresponding change in mechanical strength of FRPs with examples. The effect of microbial activity on the damage of FRP is not very much reported in literature. It is known that sulfate-reducing bacteria (SRB) are the most damaging microbes for FRP. In conclusion, it is highlighted that vinyl-ester-based FRPs using glass and carbon fibers are best for marine application. To determine the realistic service life in marine environment, Vinyl Ester- FRP (VE-FRP) are to be simultaneously studied for damage due to sea water and the microbes such SRB.

Structural Health Monitoring of Existing Reinforced Cement Concrete Buildings and Bridge Using Nondestructive Evaluation with Repair Methodology

Sustainable development means the utilization of resources at a rate less than the rate at which they are renewing. In India infrastructure industry is growing rapidly due to globalization and raising awareness. In the present study, challenges faced by countries like India are to sustain the existing expectations with limited resources available. Reinforced Concrete (RC) structure may suffer several types of defects that may jeopardize their service life. This chapter deals with condition assessment and repair of RCC (G+3) building situated at Northern part of the country. There are various techniques available for repair and rehabilitation of reinforced concrete structures. From a maintenance point of view, it is essential to take up the strength assessment of an existing structure. So, to find out the reason behind the deterioration of the concrete structures some of the NDT and partially destructive technique are used. The NDT tests conducted during this study are Rebound Hammer, Ultra-sonic Pulse Velocity, Concrete resistivity Meter, Ferro-scanning and Carbonation, etc. This chapter helps to explains, how identified the different parameters of distress building like strength, density, level of corrosion and amount of reinforcement. On basis of these results, apply a repair methodology to revert back the strength parameters of the buildings.

Electrical, Piezoresistive and Electromagnetic Properties of Graphene Reinforced Cement Composites: A Review

Due to their excellent combination of mechanical and physical properties, graphene and its derivatives as reinforcements have been drawing tremendous attention to the development of high-performance and multifunctional cement-based composites. This paper is mainly focused on reviewing existing studies on the three material properties (electrical, piezoresistive and electromagnetic) correlated to the multifunction of graphene reinforced cement composite materials (GRCCMs). Graphene fillers have demonstrated better reinforcing effects on the three material properties involved when compared to the other fillers, such as carbon fiber (CF), carbon nanotube (CNT) and glass fiber (GF). This can be attributed to the large specific surface area of graphene fillers, leading to improved hydration process, microstructures and interactions between the fillers and the cement matrix in the composites. Therefore, studies on using some widely adopted methods/techniques to characterize and investigate the hydration and microstructures of GRCCMs are reviewed and discussed. Since the types of graphene fillers and cement matrices and the preparation methods affect the filler dispersion and material properties, studies on these aspects are also briefly summarized and discussed. Based on the review, some challenges and research gaps for future research are identified. This review is envisaged to provide a comprehensive literature review and more insightful perspectives for research on developing multifunctional GRCCMs.