Behavior of sustainable Reactive Powder Concrete by Using Glass Powder as a Replacement of Cement

Every year, the world produces one million tons of glass garbage. Once the glass has been broken down, it is dumped in landfills, where it will remain inert for hundreds of years. glass is mainly made of silica. For long-term infrastructure development, ground glass as a partial cement substitute may be a major advance (environmentally friendly, energy-saving, and economic). Secondary calcium silicate hydrate is expected to be produced when glass waste is crushed into microscopic particles and then reacts with cement hydrate through pozzolanic interactions (C-S-H). There were experiments done on concrete utilizing (0-35 per cent) ground glass and superplasticizer, silica fume, fine sand and fibres, with the water to binder (cement + glass) ratio maintained constant for all degrees of replacement on compressive strength, modulus of elasticity and tensile strength. Steel is a fixed quantity that applies to all conceivable configurations. Concrete cube samples were made and tested for strength (28 days curing). It was discovered that the recycled glass concrete outperformed control samples in compressive strength tests. Compressive strength, tensile strength, and modulus of elasticity are all greatest in the 25 per cent glass powder. It was decided that using recycled glass trash in place of 25 per cent of the cement was a good idea because of the economic and environmental advantages.

Experimental Study on Shear Behavior of Reactive Powder Concrete Beam

In order to study the shear behavior of high-strength reinforced Reactive Powder Concrete (RPC) beams, eight test beams were designed and fabricated for the shear test under symmetrical concentrated load. By observing the development and failure mode of diagonal cracks, the influence of shear span ratio, stirrup ratio, and longitudinal reinforcement ratio on the cracking load, shear capacity, and deflection of the test beam is analyzed. The results show that: in a specific range, the shear capacity increases with the increase of stirrup ratio and longitudinal reinforcement ratio and decreases with the increase of shear span ratio. The shear span ratio has the most significant influence on the component’s failure mode and deformation capacity. The increase of the stirrup ratio can improve the deformation capacity of the component in a specific range. It is conservative to use the code to design concrete structures to calculate the shear capacity of high-strength reinforced reactive powder concrete beams. It is suggested that the shear calculation formula suitable for high-strength reinforced reactive powder concrete should be adopted to make the theoretical calculation results closer to the measured values.

Microstructure and Mechanical Property Evaluation of Dune Sand Reactive Powder Concrete Subjected to Hot Air Curing

The use of different sustainable materials in the manufacture of ultra-high-performance concrete (UHPC) is becoming increasingly common due to the unabating concerns over climate change and sustainability in the construction sector. Reactive powder concrete (RPC) is an UHPC in which traditional coarse aggregates are replaced by fine aggregates. The main purpose of this research is to produce RPC using dune sand and to study its microstructure and mechanical properties under different curing conditions of water curing and hot air curing. The effects of these factors are studied over a long-term period of 90 days. Quartz sand is completely replaced by a blend of crushed and dune sand, and cement is partially replaced by using binary blends of ground granulated blast furnace slag (GGBS) and fly ash (FA), which are used alongside silica fume (SF) to make a ternary supplementary binder system. Microstructural analysis is conducted using scanning electron microscopy (SEM), and engineering properties like compressive strength and flexural strength are studied to evaluate the performance of dune sand RPC. Overall, the results affirm that the production of UHPC is possible with the use of dune sand. The compressive strength of all mixes exceeded 120 MPa after 12 h only of hot air curing (HAC). The SEM results revealed the dense microstructure of RPC. However, goethite-like structures (corrosion products) were spotted at 90 days for all HAC specimens. Additionally, the use of FA accelerated the formation of such products as compared to GGBS. The effect of these products was insignificant from a mechanical point of view. However, additional research is required to determine their effect on the durability of RPC.