Journal of Civil and Environmental Engineering

Concrete is the commonly used building material. It has to be poured into the formwork to take the appropriate shape of a structural element. Therefore, the used formwork affects the surface parameters and final properties of cementitious materials. This paper aims to study the effect of formwork surface texture parameters and release agents on the surface of cementitious materials. Including a reference formwork (F17-Ref), mineral oil (F17-MO), vegetable oil (F17-VO), polyethylene terephthalate coated (PET), and polymeric coated (C20C27) formworks were prepared. For this purpose, pre-crack demolding tests on cement paste samples and pull-off demolding tests on concrete samples were conducted to analyze the adhesion between cement paste/concrete and formwork. The results highlight that the specimens with polymeric-coated plates had the lowest surface roughness values, but all of the coated formworks had almost similar surface energy. In addition, the experimental tests confirmed that samples subjected to PET and F17-VO formworks presented lower adhesive force. As a comparison vegetable oil showed better demolding behavior compared to mineral oil. On the other hand, the visual aspect reveals that the cementitious surfaces subjected to polymeric- coated formworks are shiny and smooth compared to the opaque surface of oil-coated formworks. Finally, based on the outcomes, the PET-coated formwork could be recommended as an alternative solution to release agentss.

Crushed Over-burnt Clay Bricks (COBB) is a promising alternative to the natural gravel aggregate in Light Weight Concrete (LWC) production because of its high strength-to-weight ratio. In addition, COBCB is considered a green aggregate by solving the problem of disposing of this solid waste. in this paper, a total of fifteen Reinforced Concrete (RC) beams were constructed and tested up to failure. The experimental program was classified to five groups, the first group was casted with Normal Weight Concrete (NWC) as control, and the remaining four groups were casted with LWC. The test parameters were concrete type; reinforcement ratio and silica fume (SF) content. The behavior of beams was evaluated in terms of crack patterns, failure mode, ultimate deflection, and ductility. Based on the experimental results, the resulting concrete showed that it satisfies the requirements of LWC in terms of unit weight and strength. In addition, increasing the reinforcement ratio and silica fume content increased overall beam performance. The results revealed that measurable enhancements to the majority of the performance characteristics of LWC beam by adding SF. Thus, using COBCB as a coarse aggregate has successfully been used to produce good quality lightweight concrete. Both ACI 318-14 and CSA-A23.3-14 give acceptable for predicting cracking moment, ultimate capacity and mid-span deflection.

In India, the construction industry is one of the largest industrial sectors. The importance of construction automation has grown rapidly in developed countries. The infrastructure project requires more numbers of skilled labor, good quality of work, increased productivity, etc. Studying recent applications and projects for using robots and automation in the construction industry In today's world there is a lot of demand for investment in construction to support the economic development and social transformation with new homes, offices, industry, schools, hospitals, and infrastructure In this review paper automation and robotics construction is in our opinion an exceptional solution to build faster and more efficient civil designs nowadays. The emphasis is given to the effect of automation and robotics in construction technology.