A review of recycled aggregate in concrete applications (2000–2017)

There are number of water purification techniques but the adsorption is one of the most simplest, effective and economical method for wastewater purification. In this article a large number of solid adsorbents such as Natural adsorbents, Agricultural Wastes, Industrial wastes, Biomass, Nanoadsorbents: Carbon based nanomaterials, Nobel metal based nanomaterials, Metal oxide based nanomaterials, Spinel ferrite based nanomaterials, Nanocomposites, Dendritic polymers; Geopolymer cement have been discussed for the removal of different pollutants from waste water. Removal of Fluoride, Phosphate, Nitrate and Radionuclides from wastewater has also been reviewed in this article. Adsorption isotherm models, kinetic models, thermodynamic parameters and adsorption mechanism have also been discussed. The present article lists different type of adsorbents and reviews state-of-the-art of the removal of different pollutants from water. The efforts have been made to discuss the sources of contamination and toxicities of pollutants. Adsorption mechanisms responsible for pollutants removal by different adsorbents have been reviewed. Attempts have also been made to point out the advantages and drawbacks of adsorbents and the future research needs in the area of water purification by adsorbents.

Water purification by using Adsorbents: A Review

Construction and demolition waste generation and properties of recycled aggregate concrete: A global perspective

A comprehensive laboratory evaluation of the geotechnical and geoenvironmental properties of five predominant types of construction and demolition (C&D) waste materials was undertaken in th...

https://researchbank.swinburne.edu.au/file/9bbb0fa6-5557-4c65-ada9-7a360c041032/1/PDF (Accepted manuscript).pdf

Geotechnical and geoenvironmental properties of recycled construction and demolition materials in pavement subbase applications

A review of waste products utilized as supplements to Portland cement in concrete

The growing rate of plastic waste generation is becoming a global concern due to the adverse impacts of plastics on the environment. Recycling and reusing plastic waste has been identified as a sustainable approach to mitigate the environmental concerns associated with landfilling of plastics. This study aims to evaluate the effect of the addition of waste polyethylene terephthalate (PET) on the thermal conductivity, resilient modulus, and strength properties of recycled concrete aggregate (RCA) as an alternative pavement construction material. A suite of laboratory tests including thermal conductivity, repeated load triaxial, unconfined compressive strength, and triaxial shear tests were undertaken to evaluate the effect of up to 10% waste PET on the performance of RCA as a pavement material. A relatively simple, yet robust, resilient modulus constitutive model was developed for RCA/PET blends using the multivariate adaptive regression spline (MARS) approach. The proposed model incorporated thermal conductivity, unconfined compressive strength, confining stress, and deviator stress for modeling the resilient modulus response of the RCA/PET blends. A unique feature of the developed model is the incorporation of thermal conductivity as model input. Several verification phases were conducted to validate the accuracy and reliability of the MARS model. The performance of the MARS model was compared with a neural network model to further evaluate the predictive capability of the developed model. The results indicated that the MARS model was an efficient and accurate tool in predicting the resilient modulus of recycled material blends. The experimental and numerical investigations aimed to provide novel insight into the thermal and mechanical properties of recycled materials to expand their usage in pavement and geotechnical applications.

Thermal and mechanical characteristics of recycled concrete aggregates mixed with plastic wastes: experimental investigation and mathematical modeling

Washed recycled sand derived from construction and demolition wastes as engineering fill materials

In this research, a natural kenaf geogrid was used to reinforce recycled concrete aggregate (RCA) as a base/subbase material. The interface shear behavior of kenaf geogrid-reinforced RCA was invest...

Evaluation of Interface Shear Strength of Natural Kenaf Geogrid and Recycled Concrete Aggregate for Sustainable Pavement Applications

Unpaved cement-stabilized roads are commonly used for vehicular transportation in the rural areas of developed and developing countries. The high cement content of such roads, however, reduces the tensile fatigue life, especially at locations with a large strain level, resulting in the occurrence of sudden failure due to the initiation of cracks. In order to mitigate this current shortcoming, natural rubber latex (NRL) was studied in this research as an environment-friendly additive for cement stabilization works. The addition of NRL in a liquid state was found to be convenient for fieldwork implementation. The effect of influence factors was studied in this research, which included types of soil, NRL replacement ratio, water content, cement content and compaction energy on unconfined compressive strength (UCS), indirect tensile strength (ITS), and indirect tensile fatigue life (NF). Portland cement (Type I) contents were varied to 3%, 5%, and 7% by weight of dry soil, and NRL replacement ratios were varied to 10%, 15%, 20%, 25%, and 30% by weight of liquid admixture of water and NRL. The UCS, ITS, and NF values were found to increase when increasing the NRL replacement ratio, up to the highest value at the optimum NRL replacement ratio. The maximum ITS, which is directly related to UCS, was found at optimum liquid content (OLC). Although the cement-NRL-stabilized samples exhibited higher total deformation under a particular fatigue tensile stress, the plastic deformation was found to be significantly lower when compared with cement-stabilized samples at similar cement contents. This indicates that NRL replacement improves the capacity to withstand the developed plastic strain against fatigue. Furthermore, the CO2-e emission values for cement-NRL-stabilized soil were found to be lower than that of cement-stabilized soil at a similar ITS. 

Arul Arulrajah

Papers

Thermal and mechanical characteristics of recycled concrete aggregates mixed with plastic wastes: experimental investigation and mathematical modeling

Washed recycled sand derived from construction and demolition wastes as engineering fill materials

Evaluation of Interface Shear Strength of Natural Kenaf Geogrid and Recycled Concrete Aggregate for Sustainable Pavement Applications

Improvement of Tensile Properties of Cement-Stabilized Soil Using Natural Rubber Latex

Vibro replacement design of high-speed railway embankments