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This paper represents an experimental investigation of the layered concrete beam. It contains studying the possibility of using the mortar intervention with layers of glass fibre at the tension zone in a loaded supported concrete beam. To produce a beam with less weight than the beam with all Normal concrete and detecting the effect of this replacement on beam properties. A rectangular beams section (150*200*1000)mm cast with NSC (normal strength concrete) at compression zone and mortar with layers of 3D glass fibre used as a part of the tension zone. The produced beams are layered beams with a lighter weight than the homogenous RC beam. Three deferent levels of the replaced layers (1/3,1/2, and 2/3 of the beam thickness) were studied, all beams were tested under Two point load till failure. The maximum load capacity result shows an apparent lowering in the load capacity of the beam, but as the lightweight layer increases, this lowering in the load capacity becomes less. for (1/3,1/2 and 2/3) of the beam thickness replace with mortar and 3D textile fibre, the lowering percentage of failure load compare with the homogenous reinforced concrete beam are (33.04%, 27.18%, and 19.73%), and the lowering in weight is (5.45%%, 9.07%, and 12..92%) for the same sequence, respectively. Stiffness, ductility and toughness of all beams are tested. An apparent lowering in the stiffness value of the layered beams is recorded with the reference ones. At the same time, it shows an increase in the toughness and toughness value.

Recently, the constructions industry begins to make concrete more sustainable, side by side, with making its high performance. This paper aims to investigate the effect of (Metakaolin and Micro Silica) when they replace cement by (8, 12 and 16) % and (6, 9 and 12) % respectively, recycled steel slag when replaces fine aggregate by (10, 20 and 30) %, and recycled mosaic tiles when replaces coarse aggregate by (33.33, 66.67 and 100) % each one another on the slump, density, absorption and compressive strength of concrete. The experimental results showed that the maximum reduction ratio of cement reach (17%) (8% of metakaolin and 9% Micro Silica) while the optimum percentage of mosaic tiles and steel slag is (100%) and (20%) respectively. The optimum percentages obtained are combining to produce three basic green mixes: 1) 17% (8% of Metakaolin and 9% of Micro Silica) only, (2) A mix containing 17% of (Metakaolin and of Micro Silica) plus 100% of recycled mosaic, (3) 17% of (Metakaolin and Micro Silica), 100% of recycled mosaic and 20% of slag. Compressive strength at (7, 28, and 60) days, modulus of rupture at (28) days, absorption, fresh and hardened density are investigated. The best improvement in compressive strength compared with reference concrete was recorded (20.06, 10.855 and 9.983) % at (7, 28 and 60) days respectively for the mix containing (17% of cementitious materials plus 100% of recycled mosaic) while the ultimate flexure strength (24) % appeared in green mix containing (17% of cementitious materials, 100% of recycled mosaic and 20% of slag). Generally, an inverse relationship between density and absorption in all trail mixes which are conducted.

This research reviews a statistical study to check the conformity of aggregates (Coarse and Fine) was used in Kirkuk city to the requirements of the Iraqi specifications. The data of sieve analysis (215 samples) of aggregates being obtained from of National Central Construction Laboratory and Technical College Construction Laboratory in Kirkuk city have analyzed using the statistical program SAS. The results showed that 5%, 17%, and 18% of fine aggregate samples are passing sieve sizes 10 mm, 4.75 mm, and 2.36 mm, respectively, which were less than the minimum limit allowed by the Iraqi specifications for each sieve. The percentages passing sieve sizes 1.18mm, 600micrometers, and 300micrometers were more than the upper limit of specification by 5%, 20%, and 30% respectively. The samples were passing sieve sizes 1.18mm, and 600micrometers less than the minimum limit of specification by 17%, and 4%, respectively. The results showed that the deviation in a sieve size of 150 micrometers for the upper limit of the specification performs 2% of the total number of samples. For Coarse aggregate, the samples passing sieves size 37.5mm and 20mm were comforting the Iraqi specifications by 100% and 83% respectively, it has found that the samples were passing sieve sizes 10mm was 5% was more than the higher limit of Iraqi specifications, and 27% of these samples were less than the minimum limit, whereas sample passing sieve size 5mm was 1% which is more than the upper limit of the Iraqi specification. As a result of statistical analysis of data for fine aggregate, it has found that the samples were passing sieve sizes 10mm, 2.36mm, 1.18mm and 150micrometers conforming from statistical point of view the Iraqi specifications, whereas the samples were passing sieve sizes 4.75mm, 600micrometers and 300 micrometers didn’t conform. Statistical analysis of the results of the coarse aggregates also showed that conforming to sieve sizes of 37.5mm and 20mm and didn’t conform for sieve sizes 10mm and 5mm.

In this research, trial mixes were conducted according to Self-Compacted Concrete (SCC) specifications, a mix that gave a higher compressive strength to the age of seven days has been selected. Then after selecting the appropriate mix, concrete samples had poured and were distributed into five groups; each group consists of six cubes, six cylinders, and six prisms. The samples of each group are testing for compressive, tensile splitting, and flexure strengths respectively for the ages of 7, 14, 28, 60, and 90 days respectively. Before of conduction of destructive tests, the samples were tested using ultrasonic waves to determine the relationship between the concrete strength and pulse velocity and in the same way for all ages in above. Experimental results showed that, all concrete mechanical properties have improved, and the maximum improve was in flexural strength followed by compressive strength and tensile splitting strength. The cube compressive strength increased according to (G1 at 7 days curing) from 34.3% to 71.8%, the percentage of increase of tensile strength according to (G1 at 7 days curing) from 16.8% to 64.3% , modulus of rupture increased according to (G1 at 7 days curing) from 34.6% to 98.7% for ages (14, 28, 60, 90 days) respectively. Pulls velocity increased according to (G1 at 7 days curing): For cube from 5.1% to 23.9%, for cylinder from 21.4% to 40.3%, for prisms from 7.1% to 29.2%.

Depolymerization reaction is considered one of the most significant ways of converting waste polyethylene terephthalate in to terephthalic acid. The water polyethylene terephthalate bottle waste was collected from different places in Baghdad. The collection step shows that there is plenty amount of polyethylene terephthalate suitable to be an important source of terephthalic acid production. PET plastic waste converting to terephthalic acid by depolymerization process was examined. The effect of ethylene glycol amount, reaction time (up to 90 minutes) and reaction temperature (from 70 to 170° C) on the polyethylene terephthalate conversion was obtained. The kinetic study shows that the ordination of the depolymerization reaction of PET is first order irreversible reaction with 31103.5 J/mole activation energy. A 97.9 % terephthalic acid purity has been obtained by purification with N, N-dimethylformamide.

Depolymerization reaction is considered one of the most significant ways of converting waste polyethylene terephthalate in to terephthalic acid. The water polyethylene terephthalate bottle waste was collected from different places in Baghdad. The collection step shows that there is plenty amount of polyethylene terephthalate suitable to be an important source of terephthalic acid production. PET plastic waste conversion to terephthalic acid by depolymerization process was examined. The effect of ethylene glycol amount, reaction time (up to 90 minutes) and reaction temperature (from 70 to 170° C) on the polyethylene terephthalate conversion was obtained. The kinetic study shows that the ordination of the depolymerization reaction of PET is first order irreversible reaction with 31103.5 J/mole activation energy. A 97.9 % terephthalic acid purity has been obtained by purification with N, N-dimethylformamide.

The investigation into the effect of mesh size in nonlinear 3D-analysis of reinforced concrete beam under dynamic load presents in this paper. The behavior of reinforced concrete beam under dynamic loads are supported by intensive numerical simulations, and the effect of various parameters on the results is of great interest. Finite element simulations were performed in the nonlinear dynamic domain with modified concrete and steel constitutive models. To eliminate the dependence of the computed results on the mesh size, a procedure for calculating the ultimate tensile strain of concrete was developed and implemented into nonlinear dynamic analysis. The proposed model gives good agreement with the experimental results. In particular, the new model can be used effectively with relatively mesh size in reasonable accuracy.

This study is an application of optimization method to the structural design of tunnels, considering the total cost of the tunnels as an objective function with the properties of the tunnel and soil unit weight, height of soil above tunnel, height of water above tunnel and tunnel radius, as design variables. A computer program has been developed to solve numerical examples using the ACI code equations , requirements and criteria in concrete design. The results shown that the minimum total cost of the tunnel increases with the increase of the soil unit weight and tunnel radius, and decreases with the increase of the height of water above tunnel.