The use of recycled aggregate to reduce the over-exploitation of raw aggregates is necessary. This study analysed and categorised the properties of water-washed, fine and coarse, recycled aggregates following European Normalization (EN) specification. Because of their adequate properties, zero impurities and chemical soluble salts, plain recycled concrete was produced using 100% recycled concrete aggregates. Two experimental phases were conducted. Firstly, a laboratory phase, and secondly, an on-site work consisting of a real-scale pavement-base layer. The workability of the produced concretes was validated using two types of admixtures. In addition, the compressive and flexural strength, physical properties, drying shrinkage and depth of penetration of water under pressure validated the concrete design. The authors concluded that the worksite-produced concrete properties were similar to those obtained in the laboratory. Consequently, the laboratory results could be validated for large-scale production. An extended slump value was achieved using 2.5–3% of a multifunctional admixture plus 1–1.2% of superplasticiser in concrete production. In addition, all the produced concretes obtained the required a strength of 20 MPa. Although the pavement-base was produced using 300 kg of cement, the concrete made with 270 kg of cement per m3 and water/cement ratio of 0.53 achieved the best properties with the lowest environmental impact.

The In Situ Combustion Pilot Project (ISCPP) is an ongoing testing effort aimed at assessing the efficacy of this thermal process to increasing recovery factor in the exploitation of heavy oil reservoirs from Orinoco Oil Belt (Venezuela). The process is expected to produce 3 to 7 million cubic feet/d of combustion gases, with an anticipated composition of 20% CO 2 (g) and 80% N2(g). As an option for Carbon Capture and Storage of produced CO 2 , mineral carbonation in caustic byproducts (liquor and red mud) from alumina production was assessed at lab scale. Byproducts were characterized showing pH values 12 -14 and important quantities of NaOH. Caustic liquor and red mud were exposed to gas blends (ambient pressure and temperature) with 10 and 20% CO 2 (g) in N 2 (g), as well as pure CO 2 (g), until reaching pressure stabilization into liquid-gas system. Red mud suspensions with various densities were exposed as well to gas blends during several cycles. Saturation point was reached when consumption of NaOH was completed, resulting in the precipitation of Na 2 CO 3 . Results showed that caustic mud has a CO 2 capture capacity of 7.9 kg CO 2 (g)/m 3 , or 19 kg Na 2 CO 3 /m 3 reaching pH 8.3 at carbonate equilibrium.On the other hand CO 2 capture capacity of the red mud was 87 kg CO 2 (g)/m 3 . Thermogravimetric analysis of red mud (270 -670 °C) shows less than 2% mass loss which is a good indicator of actual CO 2 sequestration. ISCPP will produce around 77000 ton CO 2 (g) in 3 years of operation, and caustic liquor from alumina process will have sufficient capacity for its complete capture. Results revealed the existence of an important sink for CO 2 (g) to be produced in Orinoco Oil Belt, which would diminish as well the hazard of caustic liquor and red mud.