Utilization of oil-based drilling cuttings pyrolysis residues of shale gas for the preparation of non-autoclaved aerated concrete

The overall objective of this research project is to investigate the feasibility of incorporating oil-based drilling cuttings pyrolysis residues (ODPR) and fly ash for the preparation of non-autoclaved aerated concrete. Within this thesis, mechanical and physical properties, detailed environmental performance, and microstructure analysis were carried out. Meanwhile, the early hydration process and hydrated products of ODPR non-autoclaved aerated concrete (ONAAC) were analyzed with X-ray diffraction analysis (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). The results showed that the following optimal mix proportion is ideal for preparing ODPR non-autoclaved aerated concrete (about 600 kg/m3), that is to say, is 25-30% for fly-ash, 15-20% for ODPR, 20-30% for cement, 15-20% for quicklime and 4% for gypsum, W/S is 0.61. Furthermore, the best curing steam temperature is 80 °C. The compressive strength, dry unit weight and thermal conductivity of products can basically meet the requirements of Chinese standard GB 11969-2008. The results also showed that ODPR had a certain pozzolanic activity which could play the role of active materials. Environmental performance tests came to the conclusion that when ODPR serves as recycled aggregates and admixture for preparation of non-autoclaved aerated concrete, from the technique's perspective, it wouldn't be the substance of environmental contamination.