Papers by Sherif Al-Tersawy
Frattura ed Integrità Strutturale
Concrete containing wastes from the demolition of old deteriorated buildings are produced enormou... more Concrete containing wastes from the demolition of old deteriorated buildings are produced enormously. Concrete is a brittle matrix that is usually reinforced by ductile reinforcement such as steel bars. However, due to the susceptibility of steel to corrosion, fiber-reinforced polymers (FRP) bars are used as an alternative reinforcement. The main drawback of FRP bars is their brittleness. These two types of reinforcements, i.e. steel and glass FRP (GFRP) bars, have been used in the present work. The flexural behavior of twelve RC beams reinforced with different ratios of GFRP or steel areas containing recycled aggregate has been experimentally studied and compared with beams without recycled aggregate. The present results show that beams reinforced with GFRP and containing recycled aggregate exhibit a lower load-carrying capacity, lower first crack, and higher deflection than all beams. All GFRP RC beams exhibited brittle failure, i.e., concrete crushing in the compression zone, exc...
The problem of Egyptian agricultural land is the production of Rice Husk Ash (RHA) with a huge am... more The problem of Egyptian agricultural land is the production of Rice Husk Ash (RHA) with a huge amount and nothing made to reuse of it that made a lot of environmental problems. The average quantity of RHA produced in Egypt annually ~6 million ton and only 17% of it reused and the rest burnt causing a significant environmental problem. On the other hand, a lot of new water treatments plants (WTP) came into work producing many sludge quantities. The reuse of the sludge will reduce the burden on the environment. The competence of using the sludge generated from WTP and the RHA produced from agricultural waste was investigated in the production of concrete. Several mixes were created to check application suitability for RHA and sludge and to determine the product best application. Concrete mixes were produced with different mixing ratios of burnt RHA and sludge ash between 0 % and 30% as a cement replacement. 10% RHA cement replacement gave a very near 28 days compressive and tensile st...
The problem of Egyptian agricultural land is the production of Rice Husk Ash (RHA) with a huge am... more The problem of Egyptian agricultural land is the production of Rice Husk Ash (RHA) with a huge amount and nothing made to reuse of it that made a lot of environmental problems. The average quantity of RHA produced in Egypt annually ~6 million ton and only 17% of it reused and the rest burnt causing a significant environmental problem. On the other hand, a lot of new water treatments plants (WTP) came into work producing many sludge quantities. The reuse of the sludge will reduce the burden on the environment. The competence of using the sludge generated from WTP and the RHA produced from agricultural waste was investigated in the production of concrete. Several mixes were created to check application suitability for RHA and sludge and to determine the product best application. Concrete mixes were produced with different mixing ratios of burnt RHA and sludge ash between 0 % and 30% as a cement replacement. 10% RHA cement replacement gave a very near 28 days compressive and tensile st...
Recently, the development in construction field due to nanotechnology materials had a significant... more Recently, the development in construction field due to nanotechnology materials had a significant inflection on the enhancement of concrete properties. Nano materials had become an important aspect for today's civil engineers. Among the nano materials presently used in concrete, nano-silica provides mechanical strength, impermeability, and durability to concrete. This unique characteristic is attributed to its high pozzolanic nature that gives it the ability to react with the fee-lime during hydration forming an additional C-SH gel. In the present work, a different content of micro silica and nano silica as partial replacement of cement in Normal and High Strength Concrete mixtures were used. It was concluded that 8% micro silica and 2% nano silica as partial replacements of cement, improved compressive strength and tensile strength of the concrete specimens seriously. In Hybrid NS+SF samples, the cement media was more compact, and the CaOH2 crystals are disappeared, and an almo...
Construction and Building Materials, 2021
Abstract In this study, experimental and theoretical work on barite concrete with nanomaterials a... more Abstract In this study, experimental and theoretical work on barite concrete with nanomaterials against gamma and neutron radiations were implemented. Besides density, radiation energy, and the type of aggregate, which are the main variables in radiation attenuation, the researchers focused on nanomaterials with a higher atomic number such as TiO2 and Fe2O3, and those with favorable filling and hydration effect such as SiO2 along with their hybridization as an addition to the barite concrete. Nanomaterials were added with 0, 1, 3, 6, and 9% of cement weight to experimentally investigate the mechanical properties, microstructure, and gamma radiation characteristics. The same mixes of elements and quantities were used in the theoretical work in addition to 12 and 15% nanomaterials and along with the material’s data of a gravel concrete from a previous work to optimize the mixes that are capable of shielding both gamma and neutrons radiations. The correlated results indicated higher experimental gamma attenuation coefficients than the theoretical ones and the good effect exhibited by the addition of the nanomaterials; especially TiO2 and Fe2O3, which added to the mechanical strength and gamma shielding of the barite concrete. The optimization process gave the required densities, moderators’ fractions, and barite-gravel content in the mix that are required to shield against both gamma and neutron radiations and proved essential in designing mixes with adequate shielding mechanism.
Archives of Civil and Mechanical Engineering, 2021
Since a lot of medical facilities are made from normal weight concrete (NWC), it became an import... more Since a lot of medical facilities are made from normal weight concrete (NWC), it became an important task to improve the radiation shielding properties of such concrete in a confrontation to radiation with special emphasis on gamma radiation type. Therefore, an experimental program was conducted to investigate the effect of nanoparticles addition on gamma radiation shielding, physical properties, and mechanical properties of NWC. Nano silica (NS), nano hematite (NH), nano titania (NT), and their hybridization were added to NWC with four different percentages of 0.5, 0.75, 1.0, and 2.0% from the cement weight. A total of sixteen concrete mixes with nanoparticles in addition to a control mix were made. The long-term effects of gamma radiation on samples representing all concrete mixes were studied to find out the consequence of exposure to gamma rays over long periods (250 and 500 days) on their mechanical properties. The experimental results showed that the single addition of each of NS, NH, or NT particles and their combination up to 2.0% improved the physical properties, compressive strength, and attenuation coefficient of NWC. The results of the hybrid nano addition showed that the synergistic phenomenon occurred in some cases. Furthermore, the scanning electron microscopy technique (SEM) was used to prove the enhancement in the microstructure of NWC as a result of the addition of NS, NH, NT, and their combination.
ERJ. Engineering Research Journal, 2014
The need for an alternative to steel reinforcement (RFT) in areas of severe environmental conditi... more The need for an alternative to steel reinforcement (RFT) in areas of severe environmental conditions and areas sensitive to magnetic fields has emerged the use of Fiber Reinforced Polymers (FRP). Experimental and analytical studies of FRP reinforcement are still less than that of steel RFT. In this study, seven slabs reinforced with local Glass Fiber Reinforced Polymers (GFRP) were tested under four points bending configuration. Load-deflection behavior, as well as strains in slabs, was recorded in order to investigate slab's ductility and flexural behaviors. The main parameters of the experimental work included RFT ratio, and shear span to effective depth ratios (L sh /d eff .) Analytical models used to predict these behaviors were implemented in order to compare the results with experimental work. The results of this research work indicated that crack behavior and load deflection curves can be simulated using analytical models and can be reasonably used for the prediction of the behavior of the tested slabs.
International Journal of Advanced Structural Engineering, 2014
The need of strengthening reinforced concrete columns, due to loss of strength and/or stiffness, ... more The need of strengthening reinforced concrete columns, due to loss of strength and/or stiffness, is an essential requirement due to variation of the loads and environmental conditions applied on these columns. Steel jackets around the reinforced concrete (RC) columns are usually made by means of steel plates covering all over the column surface area. For the value of engineering purposes, another technique was developed using steel angles at the corners of the RC columns connected with discrete steel strips. In this paper, an experimental program is designed to evaluate the improvement in loadcarrying capacity, stiffness and ductility of strengthened RC columns, concomitant with steel angles and strips. Despite of prevailing a substantially increased loading capacity and strength a pronounced enhancement in ductility and stiffness has been reported. A need for experimental test results with low value of concrete strength to mimic the local old-age structures condition that required strengthening in local countries. Seven columns specimens are tested to evaluate the strength improvement provided by steel strengthening of columns. The method of strengthened steel angles with strips is compared with another strengthening technique. This technique includes connected and unconnected steel-casing specimens. The observed experimental results describe load-shortening curves, horizontal strains in stirrups and steel strips, as well as description of failure mode. The extra-confinement pressure, due to existence of steel cage, of the strengthened RC column can be also observed from experimental results. The code provisions that predict the load-carrying capacity of the strengthened RC composite column has a discrepancy in the results. For this reason, an analytical model is developed in this paper to compare the code limit with experimental observed results. The proposed model accounts for the composite action for concrete confinement and enhancement of the local buckling of steel elements. This adopted model is simplified and applicable to practical design field. In this respect, the experimental results and those of the analytical model showed a good agreement.
Construction and Building Materials, 2012
Glass has been indispensable to man's life due to its properties, including pliability to take an... more Glass has been indispensable to man's life due to its properties, including pliability to take any shape with ease, bright surface, resistance to abrasion, reasonable safety and durability. Waste glass creates serious environmental problems, mainly due to the inconsistency of waste glass streams. With increasing environmental pressure to reduce solid waste and to recycle as much as possible, the concrete industry has adopted a number of methods to achieve this goal. Self-Compacting Concrete (SCC) may lead to evolution of a more quality controlled concrete, assuring a better workability and avoiding human errors with regard to mixing and workability issues. On the other hand, it resolves the problem of noise and vibration during installation. The object of this research work is to study the effect of using recycled glass waste, as a partial replacement of fine aggregate, on the fresh and hardened properties of Self-Compacting Concrete (SCC). A total of 6 concrete mixes were produced with cement contents 416 kg/m 3 at W/C ratio of 0.45 In this investigation it was proposed that the use of fly ash as cement replacement material of 10% and Recycled glass was used to replace fine aggregate in proportions of 0%, 10%, 20%, 30%, 40%, and 50%.
Construction and Building Materials, 2013
Abstract This paper presents the performance of reinforced concrete (RC) beams strengthened in sh... more Abstract This paper presents the performance of reinforced concrete (RC) beams strengthened in shear. Both experimental investigation and analytical models were presented. Experimental investigation was carried out on nine RC beams of three different sets, as-built beams (unstrengthened), beams strengthened with vertical carbon fiber-reinforced polymer (CFRP) wraps, and beams strengthened with inclined CFRP wraps. The main parameters investigated were concrete strength, CFRP thickness and wraps orientations (90°, 45°). The results of the experimental work indicated that externally bonded CFRP wraps enhanced the shear strength of beams significantly and that inclined CFRP configuration is more effective than vertical ones. Also, it was shown that concrete strength affects the contribution of CFRP regarding shear resistance. Experimental results were compared to analytical models, ACI 440.2R-08 and ECP 208-05. The results showed that the design approaches of both codes are almost similar.
Composites Part B: Engineering, 2013
Abstract Over the last two decades, fiber reinforced polymers (FRPs) have been widely accepted fo... more Abstract Over the last two decades, fiber reinforced polymers (FRPs) have been widely accepted for rehabilitation and strengthening of reinforced concrete structures, as FRP externally bonded for enhancement of its strength and stiffness. This paper summarizes the results of experimental studies concerning the flexural strengthening of reinforced concrete beams by external bonding of single and multiple layers of lightweight fiber reinforced plastics (FRPs) wraps. Despite a substantial increase in the loading capacity and strength have achieved, reduction in ductility has also reported as a result of de-bonding failure at the FRP and concrete interface surface. The deterioration and loss of the mechanical properties of repaired flexural beams makes the loss of bond strength at the interface surface. For this reason the need for using multilayer of FRP wraps with U-shape vertical cross wrap configuration is most efficient in redistribution of the interface bond between reinforced concrete and FRP surface. Full scale eight flexural beams were tested to achieve the strength enhancement provided by FRP single and multilayer wraps. The tested beams with single and multilayer wraps are set up using different vertical U-anchor configurations. Analytical model was developed to compare the code limit with experimentally predicted results.
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Papers by Sherif Al-Tersawy