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In this study the recycled coarse aggregate (RCA) obtained from a single source was used and the compressive strength was found to be 25 MPa before demolition. Raw recycled coarse aggregate is hand-picked from the demolished concrete rubble. Recycled coarse aggregate has old cement mortar attached to its surface so when reused in concrete, this loose old cement mortar is removed from the surface making the concrete perform poor in strength and durability. So before using in concrete, recycled coarse aggregate is being treated in various ways to enhance its strength and durability properties in concrete. In the current study, various pre-treatments methods such as Mechanical treatment (Autogenous cleaning), Thermal – mechanical method, Pre–soaking in water (Pre-Saturation), Pre-soaking in acid, Two-stage mixing approach (TSMA), Three step method, Self-healing method, Mineral admixture solution, Polymer emulsion, Microbially induced calcite precipitation and Carbonation are tested for their suitability and few recommendations are made. [ABSTRACT FROM AUTHOR]

In general, Reinforced Concrete structures exposed to much vulnerable climate leads to corrosion of the steel reinforcement, which results the huge loss of durability, serviceability. Carbonation or chlorides are the reasons of corrosion in reinforcement of steel. Carbonation is the reaction of carbon dioxide in the air with calcium in the concrete. Hence, Fibre Reinforced Polymer rebars which is resistant to corrosion can be replaced with steel reinforcement. So, from the past decade, many researchers are studying the usage of FRP rebars as they are anti-corrosive, high tensile strength, non-magnetic, lightweight, high temperature resistant, low maintenance, and durable. The FRP rebar has the disadvantage of possessing the low ductility and it is not able to bend in required shape. Hence, the hybrid reinforcement is introduced in the concrete structures to enhance the ductility and corrosion requirements. This paper will give brief review on specific application of FRP bar in terms of cost effectiveness, ductility, load carrying capacity and failure modes. [ABSTRACT FROM AUTHOR]

The durability characteristics of treated recycled coarse aggregate concrete are presented in this paper. When recycled coarse aggregate is reused in concrete, the old cement mortar connected to its surface is removed, causing the concrete to perform poorly in terms of strength and durability. So, before being used in concrete, recycled coarse aggregate is treated in a variety of ways to improve its strength and durability. In this paper various physical, chemical, mechanical and durability properties of recycled aggregate concrete are discussed. When comparing the qualities of concrete formed with 20-30% recycled coarse particles to those of normal concrete, there is no notable difference. Concretes with 50% to 100% recycled aggregates show a lower increase in compression strength from 7 to 28 days than conventional concrete containing solely raw materials. The HCl acid soaking treatment eliminated a considerable amount of mortar content, resulting in a significant increase in the characteristics of treated recycled coarse aggregate (TRCA). [ABSTRACT FROM AUTHOR]

This paper presents the use of modified method of constant voltage technique, electrical resistivity and corrosion potential measurements in determining the effectiveness of corrosion inhibitors' in concrete in arresting corrosion in the steel rebars in reinforced concrete specimens. Accelerated corrosion test is conducted on the different corrosion inhibitor mixed reinforced beams made with different cover thickness to understand the effect of cover thickness and type of inhibitor on the rate of corrosion based on the accelerated cracking initiated. Various inhibitors of corrosion, including calcium nitrite, sodium nitrite, hexamine and Diethanolamine, have been used in optimal dosage and investigated for their corrosion resistivity in concrete. [ABSTRACT FROM AUTHOR]

Fibre Reinforced Polymer has been used to eliminate deterioration of steel from corrosion, cost effectively and to make it available for all structural uses. This paper will give a review on effective type of FRP bar among Glass, Basalt, Carbon, Aramid Fibre Reinforced Polymer bars in terms of ductility, flexural performance and cost. In the study it has been found that many polymers have been used to strengthen the RC structure in various orientation of polymers for their respective strengthening criteria like moment capacity, shear capacity as they are light in weight, high tensile strength, anti-corrosive & non-magnetic. The main disadvantage of FRP bar is its brittleness. Hence, hybrid FRP bars are introduced to improve its ductility and flexure performance. Among all the polymers GFRP was cost effective, easily available and a material with required structural qualities which can replace steel partially. GFRP was used in many forms like bars, fabric sheets etc., based on the requirement and ability to develop a bond & ease of placing. However, steel could not be replaced totally but there was significant increase in strength and ductility when GFRP was used. From the study, it was concluded that the arrangement of GFRP bars shall be placed around the corners so as to enhance ductility and to avoid corrosion [ABSTRACT FROM AUTHOR]

The building industry's ever-changing dynamics have resulted in the introduction of new materials from time to time. Glass fiber reinforced polymer (GFRP) bars are gradually replacing traditional steel bars in RCC work. The traditional structures are much affected with corrosion which reduces the long-term performance in terms of flexural capacity and hence FRP (fiber reinforced polymer) are introduced in the study as they are lightweight, high tensile strength, nonmagnetic. The most disadvantage of the FRP bar is the Brittleness. Hence Hybrid reinforcement is induced to improve flexural performance and ductility. This project work was studied on a different type of FRP bars, their mechanical properties, and effectiveness. Hence from the study, it is known that GFRP is the most effective in terms of cost and performance. The adaptability of GRRP, which has a higher strength-to-weight ratio, corrosion resistance, durability, and stiffness than traditional steel bars, is responsible for this significant shift in construction practice. However, because GFRP is prone to rapid and brittle failure due to its linear stress-strain behavior, reinforcing fibers are utilized in combination to offer structural safety. [ABSTRACT FROM AUTHOR]

A feasible replacement for steel reinforcement is offered in reinforced-concrete construction Steel reinforcing corrodes with time, lowering the capacity of a reinforced concrete structure. Some concrete structures have utilized composite fiber reinforced polymer (FRP) reinforcement as a steel substitute; however, this corrosion-resistant alternative comes at the expense of the structure's flexibility. FRP reinforcement is now manufactured in a linear elastic (or brittle) state till failure. The suggested hybrid rebar is made up of multiple types of fibers that fail at different strains during the rebar's load history, allowing for gradual rebar failure. Experiments on concrete beams reinforced with glass fiber reinforced polymer are described in this paper (GFRP) The effect of mixing GFRP bars was explored in detail, and the independent behavior of GFRP reinforced beams was evaluated. In addition, existing analytical methods for predicting the shear strength of GFRP and steel fiber reinforced beams were examined and compared. Based on the findings, the best model for predicting the shear strength of GFRP reinforced beams with steel fibers were chosen and changed. [ABSTRACT FROM AUTHOR]

This paper presents the assessment of the strength at early age and automatic curing of concrete using the IoT (Internet of things). IoT can be used for SHM (structural health monitoring) and for other civil engineering applications. Evaluating the strength of concrete structures at early age is very important for a structural engineer, similarly the controlling the waste of water during continuous curing of concrete done manually is also a matter of concern. So the concept of assessing the early age strength using smart rock sensor and automatic curing using moisture sensors are installed to address the above issues in construction. The functioning of these entire processes can be monitored and controlled from remote location. [ABSTRACT FROM AUTHOR]