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In recent years, textile reinforcement has been widely researched and used in reinforced concrete beams, slabs, and thin plates. However, the design for bending is completely different from that of the shear case. The use of textile carbon yarns in place of or in addition to traditional steel stirrups to reinforce the shear has been investigated. Eight beams with dimensions of 200 mm × 300 mm × 1500 mm were used in this investigation. These beams were tested in shear under four load points. Two specimens were used with and without steel stirrups as reference specimens, while the other six beams used textile carbon yarns instead of steel stirrups. The variables of this study were the length of overlap, which was 30%, 60%, and 100%, the spacing was 90 mm and 130 mm, while inclination was 45° and 90°, and bonding with or without steel fibers. The results showed that using 100% overlap length, 90 mm spacing, a 45° angle, and adding steel fibers increased the shear capacity, increased the deflection, and made the cracking behavior better.

An alternative reinforcing shear technique was proposed during this work in place of the traditional vertical stirrups. Three reinforced concrete beams with dimensions of (200 * 300) mm and a length of 1800 mm were used. A reference control beam with traditional vertical stirrups (RCWS) and two beams reinforced with flamingo with a fixed angle of 45° and free ends (50% and 50%) from effective depth were used, while the main variable was the bonding process with concrete using a screw head (FWS) and hook (FWH). In the flamingo technique, the hook was used and the screw head was used at an equal angle of 130 degrees. A significant improvement was found in the shear capacity of the beam compared to the reference sample. Also, using a screw head made the shear capacity 13.22% higher than using a hook and improved the shear ductility, final deflection, and crushing behavior of beams made with the flamingo technique.

Textile reinforced mortar (TRM) is mainly used for strengthening of existing structural members whereas, on the other hand Textile reinforced concrete (TRC) is a technology implied in construction of new members for enhancing the structural behaviour. Application of TRM on the tension zone of the reinforced concrete (RC) slabs to improve the flexural capacity has been investigated by many researchers in the past. However, the effectiveness of textile fabrics, used as internal reinforcement in the RC slab (TRC technology) needs to be studied. The paper, therefore, presents the experimental research conducted on three one-way RC slabs specimens reinforced using textile grid. An innovative Polyacrylonitrile (PAN) based carbon textile grid was used as internal reinforcement in combination with the steel bars. Two textile-reinforced RC slabs having one and two layers of textile grid (SRC + 1T and SRC + 2T respectively) and one reference slab (SRC) was fabricated to investigate the flexural behaviour under a four-point loading system. The internal textile reinforcement layer(s) was confirmed to be effective, particularly in terms of improving the cracking load, ductility, deformability and toughness. The material ductility of SRC + 1T and SRC + 2T slabs were increased by 41% and 44% compared to SRC slab. Also, the deformability ratio was found to be greater than 4, indicating a ductile failure of textile-reinforced slabs. Further, based on the load-deflection relation, moment-curvature curves were derived. Moreover, these curves were also developed using Eurocode two prediction model. The experimental and the predicted moment-curvature curves showed good agreement.

The application of textile reinforcement to the tension zone of the reinforced concrete slabs as a means to enhance flexural capacity has been investigated by researchers in the past. However, the effectiveness of adding short carbon fibers as internal reinforcement in the textile-reinforced concrete one-way slab needs to be studied. The paper presents the experimental research conducted on four full-scale (1500×500×50) mm one-way slabs. An innovative Polyacrylonitrile (PAN) textile grid was used as internal reinforcement in combination with short carbon fibers. The first one consists of fine-grained concrete and short carbon fibers. Two textile-reinforced RC slabs have eight layers of fabric (textile-reinforced concrete (TRC) 8 L) with two percentages of short carbon fiber (0.264% and 0.528%), and one reference textile-reinforced concrete slab without short carbon fiber was fabricated to investigate the flexural behavior under a four-point loading system. The findings indicate that TRC + short carbon fiber showed significantly improved flexural capacity, load-deflection, and load-concrete strain behaviors compared with TRC. The new TRC+ 0.264% short carbon fibers (SCF) and TRC+ 0.528%SCF improved the load-bearing capacity by about 24.19% and 31.56%, respectively, as compared with TRC. Also, the intensity of the crack pattern was measured to compare the ductility of TRC+ short carbon fiber to that of traditional TRC.

The sudden incidence of shear failure in the structural elements of the concrete entails using shear reinforcement in order to enhance the ductility. This study presents the use of an innovative steel reinforcement technique in reinforced concrete beams. The steel bars were composed in a form like that of the flamingo bird. Five beams with dimensions of 200 mm x 300 mm x 1500 mm were cast, cured, and evaluated in shear under four-point bending. One beam has been reinforced using the conventional steel stirrups as a control beam, while the new flamingo technique reinforced the other four beams in the shear zone with the parameters of variation in the inclination and lengths of the lower and upper free ends. The results revealed that the use of the flamingo technique has perfectly increased the shear capacity of the beam, and ultimate deflection, increased the shear ductility and decreased the crack width.

The study aims to conduct a direct pull-out test on fifty-four cube specimens considering different variables, including the type of reinforcement (sand-coated glass fiber-reinforced polymer (GFRP) and ribbed steel bars); the type of concrete (normal weight concrete NWC and lightweight foamed concrete LWFC); the diameter of the reinforcing bars (10 mm; 12 mm; and 16 mm) and the bonded length (3∅, 4∅, and 5∅). The hybrid fiber hooked-end steel (0.4% by volume) and polypropylene (0.2% by volume), respectively were used to improve the properties of LWFC by converting the brittle failure to ductile. The results showed that in the case of strengthened foamed concrete (FC), the bond strength with steel bars was greater compared to that with the GFRP bars. The bond strength ratio between the GFRP and steel bars of the FC specimens was found to vary between 37.8–89.3%. Additionally, in all specimens of FC, pull-out failure was witnessed with narrower crack width compared to NWC. Furthermore, mathematical equations have been proposed for predicting the bond strength of FC with steel and GFRP bars and showed good correlation with the experimental results.

Textile reinforced concrete (TRC) has gained attention from the construction industry due to several characteristics such as its lightweight, high tensile strength, design flexibility, corrosion resistance and remarkably long service life. Some structural applications that utilize TRC components include precast panels, structural repairs, waterproofing elements and façades. TRC is produced by incorporating textile fabrics into thin cementitious concrete panels. However, in order to use this strengthening method in construction practice, a design model is required. Investigating the combined effect of conventional steel and textile reinforcement on the ductility behavior of composite TRC/RC one-way slab is vitally important. Therefore, the current study describes the proper methods of calculating the ductility of the composite concrete reinforced by a direct combination of conventional steel and textile reinforcement. Four methods are presented to calculate the ductility of the three considered one-way slab specimens. The three slabs having dimensions 1500 mm × 500 mm × 50 mm were reinforced by steel bars (SRC), by steel with one layer of carbon fabric (SRC + 1T), and by steel with two layers of carbon fabric (SRC + 2T). The three slab specimens were cast by the hand lay-up method, removed from the molds, cured, and then tested in flexure after 28 days using the four-point bending method. The obtained results and calculations revealed the non-reasonability of using the conventional method based on yielding of steel reinforcement as the only criterion in the ductility determination. The results also confirmed the suitability of using the energy-based method over other discussed methods in the calculation of the ductility for the hybrid reinforced members.

Strength of concrete is a primary criterion in selecting this material for a particular application. This construction material gains strength over a long period of time after pouring. Characteristic strength of normal concrete that considered in structural design is defined as the compressive strength of a sample that has been aged for 28 days. Rapid and reliable prediction for the strength of concrete would be economically and practically of great significance. Therefore; the prediction of concrete strength has been an active area of research and a considerable number of studies have been carried out. In this study, two techniques were used to propose a model which is capable of predicting the compressive strength with acceptable accuracy, these were the revolutionary support vector machine (SVM) and the multivariable non-linear regression. Support vector machine model was proposed and developed for the prediction of concrete compressive strength at early age. The variables used in the prediction models were from the knowledge of the mix proportion elements and 7-day compressive strength. The models provide good estimation of compressive strength and yielded good correlations with the data used in this study relative to nonlinear multivariable regression. Moreover, the SVM model proved to be significant tool in prediction compressive strength of lightweight foamed concrete with minimal mean square errors and standard deviation.

Lightweight foamed concrete (LWFC) is characterized as a light in self-weight, self-compacting, self-levelling, and thermal and sound isolation. But it has low strength and low ductility which leads that the application of (LWFC) in the building construction is limited. The flowability of the fresh mix of (LWFC) was evaluated by flow test. While the hardened properties of (LWFC) include, compressive6 strength, tensile6 splitting6 strength, flexural6 strength, and 6modulus of 6elasticity. This6 study6 focuses6 on the effect of the adding of silica fume and steel fibre on the mechanical properties of (LWFC). Silica fume was added as (5%) and (10%) by the weight of cement and steel fiber (0.2%) and (0.4%) of the total volume of the mix. The density of lightweight foamed concrete was 1800±50kg/ , and cement to sand ratio was (1:1) with water cement ratio (0.28). The results indicated that adding of silica fume6 and steel6 fiber6 have great effect on the mechanical properties and improve them. The addition (10%) of silica fume and (0.4%) by volume of steel fiber was the best ratio that improves the mechanical properties of the lightweight foamed concrete (LWFC). The pozzolanic index of the (5%) and (10%) silica fume was (21.9%) and (74.76%), respectively.

In construction industry, strength is a primary criterion in selecting a concrete for a particular application. Concrete used for construction gains strength over a long period of time after pouring. The characteristic strength of concrete that considered in structural design is defined as the compressive strength of a sample that has been aged for 28 days. So rapid and reliable prediction for the strength of concrete would be of great significance. Prediction of concrete strength, therefore, has been an active area of research and a considerable number of studies have been carried out. In this study, support vector machine model was proposed and developed for the prediction of concrete compressive strength at early age. The variables used in the prediction models were from the knowledge of the mix proportion elements and 7-day compressive strength. The models provide good estimation of compressive strength and yielded good correlations with the data used in this study relative to nonlinear multivariable regression. Moreover, the SVM model proved to be significant tool in prediction compressive strength of lightweight foamed concretes with minimal mean square errors and standard deviation

High Strength Concrete (HSC) is one of the most popular types of concrete used in the world. This type of concrete has a low rapid hydration of cementation materials with low w/cm and the external surrounding environment condition exposed the HSC to high autogenous shrinkage. If this shrinkage is not treated well that well led to cracking, in this case HSC need to convenient curing necessary at the earliest time. This study presents the use of Super Absorbent Polymer (SAP) as internal curing agent to eliminate shrinkage. Two types of shrinkage are tested in this study (Autogenous shrinkage and drying shrinkage). Two groups of concrete mixes(A and B) are studied in this study each group have five types of concrete mixes, four mixes with high and ultra-high compressive strength (RPC, MRPC, HSC and SCC) and the last one with normal compressive strength (NSC). Group A represent concrete mixes without SAP addition and group B for concrete mixes with SAP. SAP was added for all mixes at 0.3% by weight of cement and adding 20ml water for each gram of SAP, specimens with dimensions (40*40*160) mm were used for testing shrinkage for each mix with and without SAP, average values for two specimens was taken as a results. It was found that concrete mixes of group B have lower shrinkage than the shrinkage of concrete mixes in group A at 28 days age with reduction of autogenous shrinkage(AS) of (57%, 35%, 37%, 44.5% and 37.5%) respectively and for drying shrinkage the percentage of reduction was (89.5%, 72%, 82%, 70% and 71%) respectively, addition of SAP to concrete mixes proves to have active effect in reducing the shrinkage of concrete.