Concrete is considered as the world’s one of the strong, reliable and flexible construction material. Manufacturing of ordinary Portland cement (OPC), which is an integral ingredient of concrete, results into significant emissions of CO2 causing a potential threat of global warming. Furthermore, due to its energy intensive and heavy resource-consuming production nature, there is an urgent need to find a substitute material of OPC which is eco-environmentally, energy efficient and economical. One of such alternatives is the geopolymer concrete (GPC) which is formed with organic/inorganic materials using alkaline activation solution(s) which is generally made of alumino-silicates. GPC has also been developed for promoting the concept of ecologically sustainable concrete for green buildings. In fact, it is a pro-actively advanced construction material involving the chemical action of inorganic molecules. The new generation of GPC consumes waste materials/ by-products to meet the requirements of global sustainable infrastructure developments leading to reduction of the consumption of natural resources. This study presents an in-depth review of GPC characteristics, emphasizing on its durability characteristics, and its potential applications in view of the recent advancements in cementitious materials. The major findings of current review indicate that Geopolymer Concrete (GPC) exhibits durability properties comparable/superior to conventional concrete as evidenced by fundamental durability tests such as sorptivity, porosity, water absorption, carbonation resistance, freeze-thaw cycles, chemical attack resistance etc. These revelations highlight GPC’s strong potential for longlasting and sustainable construction, especially in aggressive and demanding environments. Voluminous investigations on GPC, encourage its utilization while few are offering opposing outcomes.
The theoretical backgrounds and numerical modelling of zinc metal corrosion and its transport through the encapsulating mortar in a galvanic anode are presented and discussed in this paper. A one-dimensional line model with a length of 2 cm that depicts the transverse distance of the encapsulating mortar was analysed for 50 hours and a zinc flux rate of 1 × 10-8 mol/m2 s. The results reveal that the pores of encapsulating mortar clog more readily due to the deposition of zinc corrosion products in the region near the zinc metal of the galvanic anode, lowering its porosity to 50 %. The pH of the encapsulating mortar decreases in regions close to the zinc metal, while it is consistent in regions away from the metal over time. This study can be used as a reference for the design of complex finite element models to give further insight into the performance of the anode system for reinforced concrete structures.
The current investigation deals with the examination of performance for concrete specimens prepared with various lightweight aggregates, such as sintered fly ash aggregate (SFA), new fly ash brick aggregate (NFBA), recycled fly ash brick aggregate (RFBA), clay brick aggregate (CBA), and recycled clay brick aggregate (RCBA) with varying percentage of replacement of natural aggregate. It is observed that compressive strength and workability decrease with the increase of replacement of natural aggregate with different aggregates prepared from fly ash and clay brick. The present study is primarily aimed at investigating the effect of elevated temperature on the concrete prepared from various lightweight aggregates. The temperature effect is studied by using the muffle furnace for two hours at 200 °C, 400 °C and 600 °C temperatures. Non-destructive tests are also done with the help of ultrasonic pulse velocity (UPV) tests to study the quality of concrete and derive the relationship between pulse velocity and strength. The physical properties, such as mass loss, and colour change, are also observed for the concrete subjected to elevated temperature
Multi walled carbon nanotubes (CNT) are extensively employed in the construction industry, particularly in concrete applications. Further studies reveal that nano aluminium trioxide (NAT) also provides good strength when added in concrete. In this work comparative analysis is being done for compressive strength to check its compression, split tensile strength and flexure strength parameters by adding 0.1, 0.3 and 0.5 % multi walled carbon nano tubes and nano aluminium trioxide respectively to the weight of cement in M40 grade of self compacting concrete. Additionally, durability aspects of self-compacting concrete, including parameters of water absorption capacity, rapid chloride penetration and acid test are examined. The findings indicate that with addition of 0.1 % multi-walled carbon nanotubes, 2 % increment is observed, whereas 0.3 % show 8 % increment and 0.5 % shows 21 % increment in strength. Other tested parameters are also showing significant increment. Similarly, the strength and durability are also enhanced when using nano aluminium trioxide, albeit to a lesser extent compared to multi walled carbon nano tubes. The cost comparison of both the nano materials is also taken into consideration which shows that around 17 lakhs INR of material cost required for 0.1 % multi walled carbon nanotubes is more when compared to 0.1 % nano aluminium trioxide required for casting 100 m3 concrete.
June 2025
Volume - 99
Number : 06
May 2025
Volume - 99
Number : 05
April 2025
Volume - 99
Number : 04
March 2025
Volume - 99
Number : 03
February 2025
Volume - 99
Number : 02
January 2025
Volume - 99
Number : 01
December 2024
Volume - 98
Number : 12
November 2024
Volume - 98
Number : 11
October 2024
Volume - 98
Number : 10
September 2024
Volume - 98
Number : 09
August 2024
Volume - 98
Number : 08
