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Many durability related problems in concrete structures are caused due to early-age cracking. Though early-age cracking is not detrimental to the structure, this will open up the way for the long-term durability issues, hence, needs to be mitigated. Cracking of such types in concrete is commonly prevented by adding fibres. Present work aims at studying the potential use of basalt fibres in controlling the shrinkage cracks at early age, otherwise this fibre is considered not suitable for use in concrete as it would degrade under alkaline environment. Further, to sustain the long-term durability, an attempt has been made to reduce the alkalinity of the concrete by replacing the cement with fly ash up to 50%. Concrete specimens made with two water to binder ratios (w/b), six replacement levels of fly ash, and one type of fibre are used for this study. Crack width and crack area generally used for evaluating the extent of shrinkage cracks are measured and analyzed. As the shrinkage cracks are very thin to measure manually, image analysis technique has been employed to measure the crack widths. Results indicate that to a greater extent cracks developed during early age has been effectively mitigated with the incorporation of fly ash. Further, it is found that basalt fibres are effective in arresting the shrinkage cracks. Furthermore, it is concluded that manual measurement will under or overestimate the crack width, hence, image analysis technique can be successfully used for measuring the crack widths.

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This work describes the experimental investigation on behaviour of reinforced GPC beams subjected to monotonic static loading. The overall dimensions of the GPC beams are 250 mm 9 300 mm 9 2200 mm. The effective span of beam is 1600 mm. The beams have been designed to be critical in shear as per IS:456 provisions. The specimens were produced from a mix incorporating fly ash and ground granulated blast furnace slag, which was designed for a compressive strength of 40 MPa at 28 days. The reinforced concrete specimens are subjected to curing at ambient temperature under wet burlap. The parameters being investigated include shear span to depth ratio (a/d = 1.5 and 2.0). Experiments are conducted on 12 GPC beams and four OPCC control beams. All the beams are tested using 2000 kN servo-controlled hydraulic actuator. This paper presents the results of experimental studies.

Green concrete is a type of concrete. It is a sustainable material used for the construction of reinforced concrete structures. Green concrete is different compared to normal concrete. Nowadays, it plays a very good role in the construction of structures. It is subjected to very low energy consumption and low resource consumption. Green concrete is a very good material for sustainable development. Concrete is made from the replacement of substituent ingredients such as cement and aggregates. In this waste materials such as agricultural or industrial wastes are placed during manufacture to produce a new concrete. Green concrete is popular worldwide due to its extraordinary properties and applications. This paper mainly deals with the importance of green concrete and its applications, advantages, and disadvantages. The results are varying for based on different structures. So, we can get all characteristics and properties of concrete structures and know their strength.