In order to achieve a sustainable mix design, this paper evaluates self-consolidating green concrete (SCGC) properties by experimental tests and then examines the design parameters with an artificial intelligence technique. In this regard, cement was partially replaced in different contents with granulated blast furnace slag (GBFS) powder, volcanic powder, fly ash, and micro-silica. Moreover, fresh and hardened properties tests were performed on the specimens. Finally, an adaptive neuro-fuzzy inference system (ANFIS) was developed to identify the influencing parameters on the compressive strength of the specimens. For this purpose, seven ANFIS models evaluated the input parameters separately, and in terms of optimization, twenty-one models were assigned to different combinations of inputs. Experimental results were reported and discussed completely, where furnace slag represented the most effect on the hardened properties in binary mixes, and volcanic powder played an effective role in slump retention among other cement replacements. However, the combination of micro-silica and volcanic powder as a ternary mix design successfully achieved the most improvement compared to other mix designs. Furthermore, ANFIS results showed that binder content has the highest governing parameters in terms of the strength of SCGC. Finally, when compared with other additive powders, the combination of micro-silica with volcanic powder provided the most strength, which has also been verified and reported by the test results.

This paper reports an experimental study carried out to investigate the effects of using metakaolin (MK) and rice husk ash (RHA) as a partial replacement material for cement, and polypropylene (PP) as an additive, on the mechanical and water absorption properties of mortar. Cement mortar was produced using various replacement ratios of metakaolin ranging from 5 to 15%, and of rice husk ash ranging from 10 to 30%, by weight of cement. The PP fiber content considered was constant at 0.3%. Compressive strength, flexural strength, water absorption, ultrasonic pulse velocity (UPV) and scanning electron microscopy (SEM) analysis are reported in this paper. Results revealed that the combination of metakaolin, rice husk ash, and PP provided a positive influence on the mechanical properties of mortar. The samples incorporating the replacement of cement with a combination of 10% MK, 10% RHA, and 0.3% PP fiber showed better mechanical characteristics than the other mortar samples. In terms of water absorption, the addition of PP fiber reduced the permeability when compared with the mixtures with 15% MK and 10–30% RHA, and results indicated a higher absorption in comparison with the mortar containing 5–10% MK.

This paper presents a comprehensive evaluation on self-compacting (SC) mortars incorporating 0, 1, 3, and 5% alumina nanoparticles (NA) as well as 0% and 30% rice husk ash (RHA) used as Portland cement replacement. To evaluate the workability, mechanical, and durability performance of SC mortars incorporating NA and RHA, the fresh properties (slump flow diameter and V-funnel flow time), hardened properties (compressive strength, flexural strength, and ultrasonic pulse velocity), and durability properties (water absorption, rapid chloride permeability, and electrical resistivity) were determined. The results indicated that the addition of NA and RHA has negligible effect on the workability and water absorption rate of the SC mortars. However, significant compressive and flexural strength development was observed in the SC mortars treated with NA or the combination of NA and RHA. The introduction of RHA and NA also reduced the rapid chloride permeability and enhanced the electrical resistivity of the SC mortars significantly. It is concluded that the coexistence of 30% RHA and 3% NA as cement replacement in SC mortars can provide the best mechanical and durability performance.

Lime-cement concrete (LCC) is a non-structural concrete in which lime and cement are used as the main binders. However, although LCC has many applications in reducing the settlement of foundations and providing a support layer for shallow foundations, little research has been conducted to evaluate its behaviour in various moisture conditions. Previous researchers have studied the feasibility of using waste tires in conventional concrete to alleviate their negative environmental impacts. However, in field projects, rubber has not been widely used because its application leads to the strength reduction of concrete. In the case of LCC, attaining high strengths is not required and thus application of waste tire particles sounds reasonable. This research evaluated the impact of various rubber powder contents on the fresh, geotechnical and durability properties of LCC at different saturation degrees induced by the capillary action and groundwater level increment, which has not been studied before. The results of more than 320 tests showed that the application of tire powder increases workability and decreases the water absorption of LCC. Moreover, all 60-day cured specimens exposed to 100% saturation degree experienced a strength reduction of less than 10% by using rubber powder contents varying from 0 to 20%. Moreover, increasing the saturation degree from 0 to 100% decreased the average compressive strength by 13.5 and 22% for 60-day cured samples of two different mix designs. The results of this research confirm that LCC containing up to 10% rubber powder could be promisingly used underneath or close to the groundwater table without its strength and geotechnical properties being jeopardized due to rubber employment and/or exposure to ground moisture.

Exposure of concrete to the atmosphere causes absorption of CO₂and carbonation via a chemical reaction between the CO₂and calcium hydroxide and calcium-silicate-hydrate reaction products inside the concrete. A greater understanding of carbonation behavior and its micro- and nanoscale impacts is needed to predict and model concrete durability, cracking potential and steel depassivation behaviors. New and sophisticated techniques have emerged to analyze the microstructural behavior of concrete subjected to carbonation. High-resolution full-field X-ray imaging is providing new insights to nanoscale behavior. Full-field nano-images provide significant insight into 3D structural identification and mapping. Nanotomographic modeling of an accelerated carbonated test specimen can also provide a 3D view of the pore structure that resides inside slag-based concrete. This is critical for better understanding of the capillary porosity and pore solution behaviors of concrete in situ. We investigated the analysis of durability properties, including the carbonation behavior of slag-based concrete, by evaluating microstructural and nanotomographic identification techniques.