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Policy makers in India have realized the importance of facility for pedestrians and non- motorized vehicles in an urban infrastructure setup. This has resulted in increased utilization of construction materials like Portland cement and crushed stone, which are not environmentally friendly and sustainable. The current study presents the development of paver blocks for pedestrian facility using different wastes. Geopolymer concrete was synthesized by fly ash and recycled asphalt pavement aggregates for making of paver blocks. Paver blocks were produced in laboratory with recycled asphalt pavement aggregate replacement levels of 0%, 20%, 40%, 60% and 80% by weight of virgin coarse and fine aggregates. The developed paver blocks were tested for dimensions and tolerances, water absorption, compressive strength and abrasion resistance as per IS15658:2006 standard. The results of the laboratory study show that recycled asphalt pavement aggregates can be introduced into geopolymer matrix to produce paver blocks of desirable quality. Furthermore, its use in pedestrian facilities provides a new avenue for managing the excessive waste, which otherwise goes in landfills, incurring loss to the paving industry. Therefore, the proposed method can help decision makers to effectively utilize recycled asphalt pavement in paving industry with environment-friendly approach. [ABSTRACT FROM AUTHOR]

The knowledge about the utility of fly ash is well known worldwide. Moreover, even though fly ash is widely and abundantly available in India, its optimal utilization is not yet achieved. This paper attempts to give clarity on the viable limit of fly ash in structural concrete. The study confirms the applicability of efficiency factor method in the mix design and strength prediction of concrete. Maximum usable fly ash percentage depends upon the strength of concrete and type of chemical admixture. Although the results presented herein may vary with change of constituent materials, type of concrete, type and power of concrete mixer, ... etc., the trend in results would remain similar and will be useful for both researchers and practicing engineers in concrete technology domain striving for sustainable construction. [ABSTRACT FROM AUTHOR]

Utilization of reclaimed asphalt pavement (RAP) in the construction industry is gaining an advantage over conventional materials in terms of sustainable credits. However, the amount of production of RAP and its utilization has no comparison. The general practice is to replace a small fraction of virgin aggregates with RAP, usually restricted to a maximum of 30%, in base layers to promote RAP usage in the pavement industry. The present study focuses on the utilization of a high proportion of RAP (>50%) substitution in virgin aggregates (VA) as a base material in low volume roads (LVR). Mixes containing 100:0, 80:20, and 60:40 proportions of RAP:VA stabilized with different dosages of fly ash were evaluated for maximum dry density (MDD), optimum moisture content (OMC), unconfined compressive strength (UCS), resilient modulus (Mr) and California bearing ratio (CBR). It was observed that the 80:20 RAP:VA design mix with 40% fly ash meets the design requirements (UCS > 1.7 MPa and CBR > 80%) specified by the Ministry of Rural Development (MoRD), Government of India, and was considered to be an optimum mix. An example is discussed to design an LVR with an optimum mix according to the Indian Roads Congress (IRC) and AASHTO methods. The results revealed that the fatigue and rutting strains are well within the permissible limits for the new mix. The new mix design proved economical, as there was a 50% reduction in base layer thickness compared with the conventional design mix. [ABSTRACT FROM AUTHOR]

Sewage sludge (SS) management has been regarded as a serious environmental and health issue around the globe, especially in developing countries like India, mainly due to the lack of proper regulatory criteria, and appropriate engineering infrastructures. The present research work demonstrates the utilization of Fly Ash (FA) in varying percentages (with an interval of 10%) with SS as brick for sustainable building material with special emphasis on dimensional Effect. The impact of dimensional effect is measured using compressive strength behaviour for a stress rate of 14 MPa/min of two different sizes of brick i.e. D1 and D2 of sizes 7 × 7x7 cm3 and 2 × 2x2 cm3, respectively. Owing to the sintering effect, the maximum strengths of 4.02 MPa and 7.6 MPa are noticed for a composition of 60% SS+40% FA for D1 and 40% SS + 60% FA for D2, respectively. According to the Indian Standards (IS) 13757: 1993, an exhibited strength of more than 3.5 MPa by any brick composition enables it to be used as a common building brick. In general, due to the formation of triangular wedges, the D2 bricks exhibited better strength for any mixing ratio of FA and SS. The added benefit in our study was lower thermal conductivity (0.48 Wm−1K−1) of the prepared fired brick implying its better insulation property. Our study uniquely highlights the possible utilization of FA for stabilizing SS for sustainable substitution of natural clay fired brick. Future study may further investigate the compositional effect of FA on the thermal and thermodynamic attributes of the bricks. Image 1 • Pioneer study on bricks that visualizes dimensional effect along with mechanical properties. • 40–60% fly ash with sewage sludge satisfies Indian codal provisions as construction material. • Thermal conductivity of synthesized brick is lower than conventional fired clay bricks. • Dimensional effect significantly influences the compressive strength behaviour. [ABSTRACT FROM AUTHOR]