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The article presents a novel computation technique for predicting the settlement of reinforcement concrete (R.C) raft foundations based on total station and precise leveling measurements. Modified inverse distance weight (MIDW) and principal component analysis (PCA) are developed to predict the nonmeasurable settlement of raft foundations and are compared to regression techniques. Wall measurements are used to verify the proposed interpolation methods. Six observation epochs were carried out over 3 years for the R.C raft foundation of a multistory building in Baltim, Egypt, which rests on clay soil, to monitor and predict the foundation settlement. The obtained results show that PCA and MIDW models outperform other models in interpolating nonmeasurable (invisible) points, while the accuracy of MIDW is the best. The developed techniques can be used to interpolate nonmeasurable (invisible) points to understand the actual behavior of foundation settlement. The monitoring building showed that the slope of the foundation in the X direction is 7.9 and 14.5% after 5 and 26 months, respectively.

This study investigates the properties of sustainable self-curing concrete (SSC) by adding volcanic powder (VP), crushed ceramic (CC), and polyethylene glycol 6000 (PEG). VP and CC are prepared from volcanic ash, as a natural pozzolanic material, and construction waste, respectively. PEG is used as an inner-curing agent. Twenty-six concrete mixtures are prepared using VP at 5%, 10%, 15%, and 20%, CC at 50%, and PEG at 1%, 1.5%, and 2% and tested after 7, 28, and 56 days. Mechanical, workability, and durability characteristics are evaluated using different tests. The bond and cohesion between aggregates and mortar are tested using a scanning electron microscope (SEM). The results show that the optimum replacement mix for enhancing strengths, by producing C-S-H, of the studied SSC is 10% VP and 1.5% PEG. This improved the compressive, tensile, and flexural strengths of SSC by 54.5%, 60.7%, and 34.9%, respectively, compared to a reference mix. Adding CC enhances the compressive strength of SSC by 41.6% and 11.5% and decreases chloride penetration by 10% and 9.1% compared to control mixes. PEG improves the mechanical, workability, and durability characteristics of SSC even with the addition of 1%. The obtained results reveal the possibility of using VP and CC in producing SSC. [ABSTRACT FROM AUTHOR]

The present article outlines a Finite Element Model (FEM) that was created and validated by comparing it to prior experimental investigations to estimate the flexural performance of HSC beams strengthened with exterior bonded, unbonded, and unbonded pre-tensioned Carbon Fibre Reinforced Polymer (CFRP) sheets in several patterns. Nonlinear analysis was performed on three-point-loaded beams using ANSYS software, incorporating the constitutive characteristics of various components (concrete, CFRP, and steel). The comparison of FE-models and experimental data, namely for load-deflection curves, crack patterns, and failure modes, revealed that the developed numerical FE-models and experimental outcomes are in good accord. There has been numerous prior research on the behavior of beams strengthened with externally bonded CFRP sheets, but few on those reinforced with externally unbonded CFRP laminates, and even fewer on HSC beams reinforced with externally unbonded pre-tensioned CFRP laminates. Therefore, the major contribution of this article is to investigate the flexural behavior of HSC beams strengthened utilizing externally unbonded pre-tensioned CFRP laminates. The analysis revealed that the bending performance of RC-beams strengthened using external unbonded pre-tensioned CFRP-laminates is quite similar to that of bonded CFRP-strengthened beams, indicating a high potential for tackling the durability issues caused by detachment of bonded CFRP-strips in such structural elements. The existence of a fully wrapped CF sheet forced the beam to develop diagonal shear cracks in the region between the wrapped CF sheet and beam supports while also enhancing the flexural cracked zone at mid-span to change from smeared to discrete fractures. The flexural fractures spread over a deeper and wider area of the beam as a result of the incorporation of a half-wrap CF laminate. Externally unbonded CFRP-sheets pre-tensioned with 45% of the CFRP ultimate strength utilizing various patterns (straight and U-wrap) performed similarly to bonded CFRP-sheets, with a slight boost in load capacity of around 4.5% and notable reduces in deflection ranging from 9.7% to 16.24%. Using exterior unbonded CFRP laminates to strengthen RC-beams resulted in a flexural capacity increase ranging from 22.3% for NC beams to 71.6% for HSC beams. [ABSTRACT FROM AUTHOR]