This research paper is accomplished to study the effect of using waste fibers in properties of concrete . Steel lathe waste fibers are added by percentages of (4, 6 and 8 %) from weight of concrete and a percentages of concrete coarse aggregate are replaced by rubber tires waste fibers in a ratios of (5, 10 and 15%) by volume . Besides to that, the combined fibers are used steel lathe waste fibers by adding (4, 6 and 8 %) with constant replacing of rubber tires waste fibers of (10 %). The results showed that adding of steel lathe waste fibers in plain concrete enhances its strength under compression about (15%) and tension about (20%), while rubber tires waste reduced both of compression about (80 %) and tension about (51%) strengths .Also the compression and tension strengths are reduced (88% and 30%) respectively with using combined fibers . The dry concrete density of lathe waste fibers concrete is (2345-2365kN/m3) , the rubberized concrete density is (2130-2240kN/m3) and for combined fibers concrete density (2025-2180 kN/m3).
This study presents an experimental research of Self-Compacting Concrete (SCC) properties containing waste plastic fibers (WPF). Adding waste plastics which resulting from cutting PET bottles as fibers to SCC with aspect ratio (l/d) equal to (28). To illustrate the effects of WPFs on the SCC, the current study was divided into two parts, the first part shows the effect of adding plastic fibers on the properties of fresh SCC, which include the ability flow, spread, passing and resistance to segregation, and the second part to evaluate the properties of hardened (mechanical) destructive and non-destructive, which include compression strength, flexural strength and ultrasonic pulse velocity test. One reference concrete mix was conducted and eight mixes contain WPF has been producing self-compacting concrete mixers containing a different volumetric ratio of plastic fibers (Vf) % percentages (0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2) %. Three cubes samples were prepared for testing the compressive strength, three prisms were prepared for the test modules of rupture, one cylinder were prepared testing the modulus of elasticity. The experiments show that adding plastic fibers to SCC leads to an increase in the compression strength and modulus of rupture at 28-day as follows (42.30)% and (73.12)% respectively for mix ratio (1.5)% in comparison with the reference mix, which represent the best ratio of fibers, as such the results of testing the fresh concrete containing waste fibers showed that adding these fibers led a reduction in workability for SCC.
The main objective of the present study is to maintain clear environment by using natural fibers that not cause pollution. Two types of Jute fibers as mat were used to produce ratting polyester composites after treating these fibers with Iraqi dolomite of 0.2, 0.5, 0.7, and 0.9 percentages % where, eight specimens were prepared. Manual casting used to prepared these specimens by using fibers of 2.8 mm diameter between two layers of Resin for all specimens. Mechanical properties tests includes creep, tensile, and hardness by Shore method where best results of creep and tensile strength reduction are given with 0.9% of Iraqi dolomite. Hardness proportional with concentration of dolomite. Physical properties tests includes color, yellowness of color, were the samples exposed to U.V of 254 nm short length wave for 150 hours. The Jute fibers affected the color while the dolomite effects were inconsiderable, also the absorption of acidic and base solutions were proportionate reversely with increasing of dolomite and fibers' mat percentage. In biological tests, the Fungus growth on composite body decreased with increasing dolomite percentage and no great lost of weight. The present study shown that the Jute fibers in the composite body and concentration of Iraqi dolomite improve the mechanical, physical, and biological properties of polyester Resin composites with Jute fibers.
In this paper, the laboratory experiments works were conducted to study the effect of adding recycle waste plastic as polyethene terephthalate PET fibers on the fresh properties as the slump test and hardened properties as a compressive strength, splitting strength, elastic modulus, ultrasonic pulse velocity (UPV), density, absorption, voids, flexural toughness and flexural rupture for the normal concrete. The parameter of this paper included percentage of fibers content (0%, 0.5%, 1%, and 1.5%). The geometric design of the PET fibers was a strip with dimensions 4mm width, 70mm length, and 0.035mm thickness. The aspect ratio of the PET fibers in this work was about 50. The results showed that the PET fibers improving the most properties of the normal concrete and on the other hand there is negative effect on some properties of concrete. There is a significant increase in flexural toughness, about 21.2%, while the compressive strength and splitting were increased by 5% and 18.8%, respectively. Besides this improving, using PET fibers conform to the principle of sustainability, which is reducing the pollution and the cost of waste plastic disposal. It’s observed that properties of concrete as a static modulus of Elasticity and density were decreased with the fiber percentage increased
Slurry infiltrated fiber concrete (SIFCON) is a relatively new high performance material and can be considered a special type of fiber concrete (FRC) with high fiber content. The matrix consists of a flowing mortar or cement slurry that must penetrate well through the network of fibers placed in the mold. SIFCON has excellent mechanical properties combined with high ductility and toughness values. SIFCON a relatively new material, is composed of mud (cement or cement and sand), water, a plasticizer (water reducer), and fibers. All previous studies have used waste steel fibers, steel fibers and other fibers, but in this study, plastic fibers were made from polyethylene terephthalate (PET) by cutting carbonated beverage bottles. The main objectives of this study are: Determination the effect of the waste plastic fiber volume ratio on the strength and deformation of (SIFCON) samples under the influence of bending loads. Both flexural strength and toughness properties were determined by testing samples (100×100×400) mm at 28 and 56 days of age. The results obtained from these tests were compared with those performed on conventional tests. Aspect Ratio equal to (36.8) and three volume ratios (3%, 5% and 7%) of the total volume of the concrete mixture were used to add fibers with different volume ratios. A conventional concrete mix was created as a reference for comparison. Bending strength and fresh concrete tests were performed. And compared with the reference mixture and according to the analysis of the results. The results showed an improvement in bending strength .It was found through the flexural examination that the flexural strength of the mixture containing fiber percentage (7%) achieved the highest strength compared to the rest of the ratios used, compared with the reference mixture (Ref.) by (32.25, 27.5)% for ages (28, 56), respectively.
Foamed concrete (FC) is a type of lightweight concrete characterized by a high void space ratio and cementitious binders. In this research, the fresh and mechanical properties of fiber-reinforced modified foamed concrete (made with fly ash, silica fume, and superplasticizer) with a density of 1300 kg/m³ were studied. Carbon fibers of different lengths (12 mm, 20 mm, and 28 mm) were introduced in two ways: as single fibers (12 mm) and as hybrid fibers combining lengths of 20 mm and 28 mm.
The results showed that the compressive and split tensile strengths increased by approximately 43% compared to the control mix (modified with additives) when using a single fiber of 12 mm at a volume proportion of 0.4%. In contrast, using hybrid fibers resulted in increases of about 65% and 66% in compressive and split tensile strengths, respectively. When compared to the single fiber method, the hybrid approach improved compressive and split tensile strengths by about 15% and 16%, respectively.
Adding fibers to the shotcrete concrete mixes is very important to increase the load carrying capacity, toughness, and reducing crack propagations by bridging the cracks. On the other hand, this fiber has an effect on the fresh and hardened properties of shotcrete. In this study, fresh properties evaluated by using slump flow, , and segregation resistance tests. Hardened properties included testing of air voids, dry density, water absorption, ultrasonic pulse velocity (UPV), compressive strength, and flexural strength. This works including two types of fibers in three forms (waste plastic (PET)fibers only, polypropylene fibers (PP) only, and hybrid fiber (PET and PP)), each form added by three percentages (0.35%, 0.7%, and 1%) by volume.The results showed that the addition of 1% of all types of fiber has a negative impact on fresh properties. Especially in shotcrete containing waste plastic fiber. Also, all specimens containing fibers showed a decrease in the ultrasonic pulse velocity (UPV) and an increase in air voids and water absorption compared to the reference specimens. Also, the results clarify that the addition of waste plastic fiber to shotcrete led to a slight decrease in dry density. The highest increasing in compressive strength of shotcrete recorded by about 8.2% with using 0.35% PP fiber and highest decreasing was 20.9% with using 1% waste plastic fiber. the highest increasing in flexural strength was 62 with using 1% PP fibers.
SIFCON is a relatively new material and consists of slurry (cement or cement and sand), water, super plasticizers (water reducers) and fibers. In all previous research, steel fibers and other types of fibers were used, but in this study, waste plastic fibers Polyethylene Terephthalate (PET) created by cutting carbonated beverage bottles were used for the first time in the production of SIFCON. Three volume ratios (3%, 6% and 10%) of the total volume of the concrete mixture were used to add fibers in different volume ratios, and a reference concrete mixture was created for comparison. Tests of compressive strength, impact resistance, ultrasound transmission velocity check and other tests were performed on the constructed models. Compared with the reference concrete, according to the analysis of the results. The results showed an improvement in the compressive strength it increased by (18.5%), an increase in the impact resistance by (416.67%), and a decrease in the velocity of ultrasound by (19.42%).
The concept of sustainability was developed in the last years and included the construction industry to solve the issues that pertaining by high consumption of natural sources, environmental pollution and high amount production of solid wastes. On the other hand, the plastics generation is growing exponentially every year, especially, types of Polyethylene Terephthalate (PET) that are used to produce soft drinks bottles, this study attempts to apply the concept of sustainability and reduce the environmental pollution by cutting the plastic bottles (PET) as small fibers added to the ordinary concrete to improve the shear and tensile strength of reinforced concrete beams. For this purpose, the experimental work was carried out to study the effect of waste plastic fibers (PET) on the shear behavior of seven reinforced concrete beams with dimensions of (100×150×1200) mm that were designed to fail in shear, the fibers percentages that were used in this study are (0.25, 0.5, 0.75, 1, 1.25 and 1.5%). Also, the influence of Polyethylene Terephthalate (PET) fibers on the mechanical properties of concrete was studied such as: workability, compressive strength, splitting tensile strength, static modulus of elasticity and ultrasonic pulse velocity.
The current research’s purpose is to examine how Ultra-High Performance Fiber Concrete (UHPFC) holds up in terms of strength and durability for strengthening purposes. For this reason, the experimental and the theoretical studies in this research attempted to assess different fresh and hardened properties of a variety of ultra-high performance combinations. Steel fibers were utilized to differentiate all of the program's combinations at percentages of 0.25 %, 0.5 %, 0.75 %, 1%, and 1.25 % by volume. Mini flow slump, compressive and flexural strength, ultrasonic pulse velocity, water absorption, and porosity tests were all used to examine the performance of the strength and durability of the material. The findings of this study's trials showed that steel fibers increased the strength of UHPFC. The steel fiber ratio of 1% gave the maximum compressive strength, whereas 1.25 percent yielded the highest flexural strength. Because the fibers function as a bridge, preventing internal breaking, the tensile test results were improved as the proportion of steel fiber rises. Through the use of the multi-objective optimization approach, the optimal ratio of fibers was chosen at the end of the laboratory work since it has the best durability and strength characteristics. Statistical software (Minitab 2018) was used to find the optimal combination of UHPFC that meets all of the requirements. The theoretical selected optimum ratio of 0.77% of fibers obtained from the optimization was evaluated and validated experimentally. The optimized mix provided 90.28 MPa, 14.6 MPa, and 20.2 MPa for compressive, splitting tensile and flexural tests respectively with better durability performance compared to other mixes prepared in this investigation.
This study was conducted to examine the impact of plastic fibers (WPFs) in an effort to improve some of the features of self-compacting concrete (SCC) using Iraqi raw materials. Waste polyethylene terephthalate fibers (waste PET fibers) from used beverage bottles were added. Some tests were carried out to determine the effects of adding WPFs on the fresh properties of new concrete, while additional tests examined the mechanical properties of hardened concrete. Because of this, self-compacting concrete blends were created with a constant water-to-binder ratio of 0.32 and a binder content of 525 kg/m3. The designated plastic fiber percentages contents were 0%, 0.5%, 0.75%, and 1% of mix volume. Self-compacting concrete mixtures' fresh characteristics were assessed for slump flow diameter, T50 slump flow concurrently, V-funnel flow concurrently, and L-box height ratio. The 28-day density, compressive strengths and flexural strength of self-compacting concretes were also measured. The use of plastic waste fibers had a slight effect on reducing the density of the produced concrete and a negative effect on the fresh properties. The compressive strengths were improved by using WPFs, with the maximum improvement equal to (11.065%) when compared to those made from the reference mix
This study presents an investigation of the mechanical properties of normal concrete reinforced with discarded steel fibers (DSFs) resulting from tire manufacturing. DSFs were added to concrete in two different volume fractions of (0.25 %, and 0.5 %), and these fibers have dimensions of (40 mm length×0.92 mm diameter). The results showed that the compressive strength of the concrete was enhanced by (8.8%, and 3.3%) by adding of DSFs. However, the workability of concrete decreased at all added ratios. While the density is slightly changed. Also, the results indicate that the modulus of elasticity shows slight increases by (3.06%, and 2.25%). Additionally, the incorporation of DSFs improves the splitting tensile strength and modulus of rupture significantly. For concrete mixes having volume fractions of 0.25% and 0.5%, the splitting tensile increased by (7.89%, and 23.68%), and the modulus of rupture increased by (6.67% and 25.58%), respectively. It was concluded that using this type of discarded fibers can improve the mechanical properties of concrete as an alternative type for other types of industrial fibers.
The design of reinforced concrete structures has traditionally relied on empirical techniques based on experience or experimental research on actual structural members. Although this approach produces a high level of precision, it is usually exceedingly costly and time-consuming. This paper studied the convergence between theoretical analysis (ACI 318-19 Equations) and numerical analysis (FEM) of eleven one way reinforced concrete slab specimens casted by shotcrete contains three types of plastic fibers including waste plastic (PET), polypropylene (PP), and hybrid (PET+PP) fibers with three addition ratios (0.35%, 0.7%, and 1%) for each type. The results concluded that the numerical analysis (ANSYS FE model) showed a good agreement with the theoretical (ACI 318-19) of one-way slab in terms of ultimate load, with a variance, and standard deviation equal to 0.00076, and 0.027 respectively. Hence, ANSYS v15 software can be used for the analysis of reinforced concrete slabs casted by shotcrete contain waste plastic fibers and polypropylene fibers.
This research investigates the impact resistance of concrete slabs with different volume perecentage replacement ratios of waste plastic fibers (originaly made from soft drink bottles) as follows : 0.5%, 1% and 1.5%. Reference mix produced in order to compare the result. For the selected mixes, cubes with (100×100×100mm) were made to test compressive strength at age of (90) days. Flexural strength (Modulus of Rupture) test was also conducted using prisms sample of (500*100*100 mm) dimensions. The low-velocity impact test was conducted by the method of repeated falling mass where 1400gm steel ball was used. The ball falling freely from height of 2400mm on concrete panels of (500×500×50 mm) having a mesh of waste plastic fiber.The number of blows that caused first crack and final crack (failure) were determined, according to the former obtained results , the total energy was calculated. Results showed an improvement in mechanical properties for mixes containing plastic fibers compared with reference mix. For compressive strength the maximum increase in compressive strength was equal to (3.2%) at age of (90) days. Flexural strengths for mixes containing plastic fiber at ages 28, and 90 days are higher than that of these of reference mix. The maximum value of increaseing was (18%) for 28 days age of test and it was equal to (26%) for 90 days age of test for the mixture with plastic fiber content by volume equal to (1%) . Results showed a significant improvement in low-velocity impact resistance of all mixes contining waste plastic fibers when comparing with reference mix. Results illustrated that mix with (1.5%) waste plastic fibers by volume give the higher impact resistance at failure than the others. The magnitude of an increase over reference mix was equal to (340%).
The main rule of this search is determining the effect adding various types of fiber to normal concrete mixes on performance normal strength concrete ,it has been used three types of fibers (glass, short steel fibers& long steel fibers)with different contents in mixes(0.5,1.0&1.5%) respectively. It had been cast (210) cubes with dimensions (100×100×100m) mm,(160) cylinders with dimensions (100×200) mm , All concrete specimens heated under different temperatures (100,200,300,400,500 &600 C°) at age 28 days, so that it had been stayed under specified temperatures about two hours then , cooled in naturally in room temperatures and tested in compressive for cubes &splitting strength for cylinders. The results stated that the fiber improve the compressive strength under fire temperatures about (87%) compare with reference mixes, and the fiber glass take little differences than steel fiber in splitting strength when its content reach (1.0,1.5%) respectively and using this types of fibers improved the properties of concrete against the fire.
The problem of discarded tires has received a lot of attention from many authors. Incorporation of rubber aggregate recycled from waste tires is one of the solutions to this issue. This research is based on evaluating fresh and hardened properties such as slump flow, T500, segregation resistance, and L-box tests, compressive strength, impact resistance, and flexural toughness. Rubber aggregate replacements in the self-compact concrete mixes was 10% by volume of fine aggregate. Additionally, both PET and steel fibers are utilized at a volume rate of 0.25%.The outcomes indicate that introducing rubber declines rheological and hardened properties, whereas incorporating hybrid fibers enhances hardened properties such as compressive strength, impact energy, and flexural toughness. The best increase impact energy was obtained at roughly 166.6% when 0.25% hybrid fibers and 10% rubber were used. 74.21 was the greatest increase in flexural toughness when 0.25% hybrid fibers (SCCH3) were used. As for the compressive strength, it was the highest by about 11%.
This main aim of this study is evaluate wide range of fresh and hardened properties of sustainable self-compacting concrete containing various types of Cement Replacement Materials with optimum contents of Polyethylene Terephthalate PET waste plastic as fibers and fine aggregate replacement. This is to evaluate effect of the two forms of PET and to determine the best CRMs could be used with sustainable SCC. such as limestone, glass powder and fly ash with high replacement rate of 70% by weight of cement were used while fourth one (kaolin) was used with replacement rate of 20%. PET fibers were added to SCC with an aspect ratio of 24.4 and 0.7% volume fraction whereas fine aggregate partially replaced by 4% of waste plastic. Four reference mixtures contained FA, LP, GP and KA only, same four mixtures contained 0.7% PET fibers by volume, and the other same four mixtures contained 4% PET fine aggregate by volume. The obtained results all tested fresh properties, which include slump flow, T500, L-Box and segregation resistance were within the limits of the specification reported in EFNERC guidelines. Further, the forms PET have an adverse effect fresh properties of SCC. As for hardened properties (compressive strength, splitting tensile strength, flexural strength and impact strength). Further, this produced type of SCC showed an range of compressive strength (15.2-31.64 MPa) at 28 days. It can be from the current study the best CRMs to be used in SCC containing PET wastes was FA in terms of most tested properties.
The present study, concern about an experimental work to study the stress-strain relationship of steel-fiber reinforced polymer modified concrete under compression. Four different mixes with weight proportions of (1:2:4) were used as; normal weight concrete (NC), polymer modified concrete (PMC) with (10%) of cement weight and two mixes of steel-fiber polymer modified concrete with (1%) and (2%) volume fraction of steel fiber, (SMPC). The influences of polymer and fiber addition on peak stress, strain at peak stress and the stress-strain curve were investigated for concrete mixes used. For all selected mixes, cubes (150×150×150mm) were made for compressive strength test at (28) days while stress-strain test was caried out on cylinders (150 mm 300 mm) at the same age. Results showed an improvement in compressive strength of polymer modified concrete (PMC) over reference mix, the maximum increase of it was (13.2 %) at age of (28) days. There is also an increase in compressive strength with increasing of steel fibers content with comparison to normal concrete, the maximum increases of it were (19.6% and 25.2%) of mixes with 1% and 2% fiber content by volume respectively. In terms of modulus of elasticity, the addition of polymer and the presence of fibers cause a significant increase in it. The peak of stress- strain curve for normal strength concrete (Mix No.1) was linear whereas it was more sharp for the other mixes. The behaviour of normal strength concrete (Mix No.1) was linear up to 20 % of ultimate strength, while for the mixes with the higher strength i.e. polymer modified concrete and fibers reinforced concrete (Mixes No.2, 3 and 4) the linear portion increases up to about 50 % of ultimate strength
This study program has been conducted to investigate the influence of adding waste plastic fibers (WPF) resulting from manual cutting for bottles used in the conservation gassy beverage on different characteristics of ordinary concrete. Cutting plastic waste by volumetric rates ranging between (0.5%) to (2%) was approved. Reference mix was produced for comparison. Tests were conducted on the models produced from waste plastic fiber concrete like compressive strength, flexural strength and splitting tensile strength. The analysis of the results showed that the use of plastic waste fibers (1%) has led to improve the properties of flexural strength and splitting tensile strength compared with reference concrete .When the( 0.75%)WPF ratio improved the compressive strength as compared with the control specimen . Compressive strength in (28 days) with fiber ratio (0.75%) WPF is higher than equal (5.1%) from compressive strength in (28 days) of reference concrete. Volumetric ratio (1%) WPF can be also observed that each of the flexural strength and splitting tensile strength increases equal (12.5 and 12.5%) respectively, from flexural strength and splitting tensile strength for the reference mix at(28day).
Nonlinear numerical analysis of nine reinforced concrete beams with dimensions (150 x 200 x 1200) width, height and length, respectively, was carried out through the finite element theory using the ANSYS software (version 15) to know the effect of different properties of layers in the one beam on the flexural behavior of reinforced concrete beams. The beams are consisting from two layers for the one cross-section. three beams are similar properties layers and the other six are with different properties layers. The beams differ among them depending on the percentage of Polyethylene terephthalate (PET) fibers added, the location of the fibrous concrete layer as well as the thickness of the layer. PET fibers were added in proportions (0%,0.5%, and 1%) from volume of the one layer, with dimension (50 x 4 x 0.3) mm length, width, and thickness respectively. All beams are reinforced with steel reinforcement (6 mm diameter at the top, 10 mm diameter for reinforcement against shear and 12 mm diameter in the tension area). The mechanical properties of each type of mixture have been studied. It was found that the different properties of the layers significantly affected the flexural behavior of reinforced concrete beams. Also the results of the numerical modeling were very close to the laboratory results obtained from the practical study, where the largest difference between the two studies was 8% and 11% for the load and deflection respectively at the ultimate point
AbstractThis study deals with establishing high-velocity impact properties of polymer –modified concrete (PMC) including Styrene-Butadiene rubber (SBR), with different weight ratios of polymer to cement: 4%, 8% and 12%. Steel fibers were also included. Sixteen (500mm) diameter, (50mm) thick discs for high-velocity impact tests were used. In addition compressive strength, splitting tensile strength, and flexural strength (modulus of rupture) were companionly recorded. In all the tests, concrete was with and without crimped steel fibers of ratio 1% by volume.In investigating high-velocity impact strength, the decrease in projectile penetration depth was (5-17%) and the scabbing area reduced (15-35%) over reference concrete.In studying PMC including 1% by volume steel fibers, an additional increase was observed in all properties. The increases were quite significant in high-velocity impact strengths. Further reduction was recorded in scabbing area of (64-95%) and penetration depth reduced (28-39%) over control specimens. The fragmentations were reduced also. The range of corresponding compressive was (48-64)MPa ,of splitting tensile strength (4.2-7.8) MPa, and of flexural strength (5-8) MP
This research includes producing compacted concrete by rolling method and the possibility for using in highway construction field with studying the influence of adding waste plastic fiber resulting from manual cutting for bottles used in the conservation gassy beverage on different characteristics of this type of concrete. For the purpose of selecting mix proportions appropriate for rolling compacted concrete (RCC). Approved design method for ACI-committee (5R-207 .1980) was selected for this research. Destroying plastic waste by volumetric rates ranging between (0.5%) to (2%) was approved. Reference mix was produced for comparison. Tests were conducted on the models produced from rolling compacted concrete like compressive strength, flexural strength and split tensile strength. The analysis of the results showed that the use of plastic waste fibers (1%) has led to improve the properties of each of the compressive strength and flexural strength and split tensile strength compared with reference concrete. Compressive strength in 28 days with fiber ratio (1%) is higher than (52.15%) from compressive strength in 28 days of reference concrete. It can be also observed that each of the flexural strength and split tensile strength increases by (17.86, 25.61)%, respectively, from flexural strength and split tensile strength for the reference mix
This research includes studying the possibility of producing a new kind of No-fines concrete by replacing granules of coarse aggregates with grains results from the fragmentation of industrial waste of polystyrene. This replacing were with different volumetric proportions of coarse aggregate, and theses volumetric ratios were equal to (5%, 10%, 15% and 25%). Waste plastic fibers (WPFs) resulting from cutting of soft drinks bottles were added for strengthening this new kind of concrete. Mixing ratio was equal to (1:5) (cement: coarse aggregate) by weight. One reference mix was produced for comparative purpose. Compressive strength, flexural strength and density tests were conducted, it was examined three samples of each examination and taking the average. Compressive strength values of the new sustainable concrete were ranged from 10 MPa to 12.4 MPa at age of test equal to 28 days, while the average value of the density of this concrete at the same age reaches 1930 kg/m3. This average value of modulus of rupture was equal to 2.36 MPa at 28-day age test.
ABSTRACT: Many of researchers study the uses of chopped worn-out tires as a replacement material to production special types of concrete. In presented work, the worn-out tires were used as fibers which have dimensions of 1×1×3 cm. The fibers used as a partial replacement from volume of coarse aggregate. Two mixes of fiber worn-out tires (F.W.T.) concrete in addition to reference mix were selected, using Partial Replacement Ratio (PRR) of 20% and 30%. The tests which were used in this study were: compressive strength, splitting tensile strength and flexural strength. It was found that incorporating of F.W.T. in concrete effected negatively on most properties of concrete, for example the percentage decreases in compressive strength relative to reference mix at 28 day were 20% and 27.3% for concrete with 20% and 30% F.W.T. by volume of coarse aggregate respectively. However, it gave good indicator to be utilized as a new construction material in many applications.
Polyethylene terephthalate (PET) fiber is a green-friendly fiber that is capable of enhancing the mechanical properties of wet-mixing shotcrete. The main purpose of this study is to see how varied volumes of waste plastic fibers (WPF) affect the flowability and mechanical properties of wet-mix shotcrete. For this aim, a variety of experimental tests based on WPF content were chosen. Fresh and mechanical tests included slump, T500, density, compressive strength, and splitting strength were applied. The results shown a improved in shotcrete performance as the WPF content increased. Among all fitting correlations, density and compressive strength revealed the strongest linear ship association. Due to greater interlocking between WPF and concrete matrix, WPF was a major use in enhancing splitting tensile strength. WPF had the most influence on splitting strength, with 23–31 percent, 7–23 percent, and 6–38 percent for 7, 14, and 28-day, respectively.
This research include the study of flexural behavior of polymer modified concrete beams containing waste plastic fiber (WPF). Fifteen reinforced concrete beams are moulded of (100*150*1300) mm dimension with different steel reinforcement ratio (ρ). These steel reinforcement ratio were (0.0038, 0.0207 & 0.0262). Styrene Butadine Rubber (SBR) was added as cement replacement by weight equal to (5%). Reinforced concrete beams classified in to five groups, each contains three beams with different (ρ) value. The first group conducted of reference concrete mix , the second group made with SBR modified concrete, while the three remaining groups were make by PMC containing (WPF) with volumetric ratio equal to (0.75, 1.25 & 1.75)%. This study includes compressive and flexural tests for concrete which was used in this research, load deflection relationships, the moment at mid-span with deflection and ductility were established. The results prove that, polymer modified concrete wich content waste plastic fiber has compressive and flexural strengths more than reference mixes as well as the PMC beams wich content waste plastic fiber have a stiffer response in terms of structural behaviour, more ductility and lower cracking deflection than those made by reference concretes and that refer to good role of styrene Butadiene Rubber (SBR) polymer and plastic fiber on the properties and behaviour of reinforced concrete beams.
Ferrocement is a type of concrete made of mortar with different wire meshes. It has wide and varied applications in addition to its strength and durability. This research aims to combine ferrocement and sustainability, as over time, the consumption of plastics, especially plastic bottles, has increased and has serious negative effects if buried, burned, or chemically analyzed. Therefore, this research aims to benefit from this plastic waste and introduce it into the construction field by using plastic waste fibers in the concrete mixture instead of cement at a rate of 0.5% and 1% by volume. This research studied the mechanical properties of nine samples of ferrocement beams with dimensions of 1200 × 200 × 150 mm3. A longitudinal hole with a diameter of 50 mm was drilled in different places of the beams and filled with lightweight concrete to facilitate the use of the hole in service passes when drilled, with a study of the initial cracking loads and the resulting deflection in addition to the failure modes and the deflection resulting from the maximum load. The results showed an improvement in load resistance with an improvement in deflection at the maximum load, In addition to an increase in the improvement of Toughness and Stiffness of ferrocement beams.
Abstract:Many of researchers study the uses of chopped worn-out tires as a replacementmaterial to production special types of concrete. In presented work, the worn-out tireswere used as fibers which have dimensions of 1×1×3 cm. The fibers used as a partialreplacement from volume of coarse aggregate. Two mixes of fiber worn-out tires(F.W.T.) concrete in addition to reference mix were selected, using PartialReplacement Ratio (PRR) of 20% and 30%. The tests which were used in this studywere: compressive strength, splitting tensile strength and flexural strength. It wasfound that incorporating of F.W.T. in concrete effected negatively on most propertiesof concrete, for example the percentage decreases in compressive strength relative toreference mix at 28 day were 20% and 27.3% for concrete with 20% and 30% F.W.T.by volume of coarse aggregate respectively. However, it gave good indicator to beutilized as a new construction material in many applications.
Today waste plastic bottles are spread widely throughout our world especially in Kurdistan, an autonomous region in Iraq. These waste products cause many environmental problems and at the same time some soils are weak and need reinforcement using cheap materials such as Polyethylene terephthalate (PET) waste plastic bottle. Use of waste plastic bottles as a reinforcement of soil is highly recommended to reduce the amounts of plastic waste, which creates a disposal problem. In this study an attempt was made to use plastic fibres produced from waste bottles to reinforce sandy soil. This can solve both environmental and geotechnical problems. In the research, the effect of plastic fibres content as well as fibre length on shear strength parameters (cohesion and internal friction) were experimentally predicted using the direct shear test method so as to improve bearing capacity of weak soils. The results showed that under low normal stress the inclusion of plastic fibres increased both angle of internal friction and cohesion; however, under high normal stress (greater than 100 kPa) the cohesion increased and the internal friction was roughly unchanged. Also, it was concluded in this study that the suitable amount of fibers that can be added to weak soils is 1% of dry weight of sand.
Abstract This research studies the effect of adding steel fiber in two percentage 0.5% and 1% by volume on plain structural lightweight concrete (SLWC) produced by using crushed bricks as coarse lightweight aggregates (LWA) in a lightweight concrete mix designed according to ACI committee 211-2-82 with mix proportion 1:1.12 :3.35 by volume .The wc equal to 0.5 and cement content 550 kgm3. Different tests where performed for fresh and hardened SLWC such slump test ,fresh and hardened unit weight ,compressive strength and two indirect tests of tensile strength (splitting tensile and flexural strength). The results demonstrated that the effect of addition of steel fiber was more pronounced on the tensile strength of SLWC than the compressive strength of such concrete .The maximum increase of compressive ,splitting tensile and flexural strengths at 28-days were 38.8,77.12 and 111.2 % in the SLWC containing 1% fiber. On the other hand the rate of strength gain between 3 and 28 days was constant on compressive strength of plain concrete and that containing steel fiber while this rate was clearly increase on tensile strength especially flexural strength.
Abstract: This research is devoted to investigate the behavior of steel fiber reinforced concrete members subjected to blast loading. Material nonlinearity due to nonlinear response of concrete in compression, tensile cracking, strain softening after cracking, crushing of concrete and the yielding of steel reinforcement are considered. Three-dimensional finite element is used with eight and twenty-node are hexahedral isoparametric brick element for the spatial discretization. In the idealization of the reinforced concrete structures, the steel reinforcement is incorporated in the concrete brick element as a smeared layer assuming perfect bond. Concrete is modeled as an elasto-viscoplastic model in compression and as a linear elastic strain softening in tension. The steel reinforcement is assumed to have uniaxial properties in the direction of the bars. A classical elasto-viscoplastic model is used to model the reinforcement. Some numerical problems are solved and compared with other studies to verify the applicability and accuracy. Parametric study to investigate the effect of some important parameters has been carried out. The results showed that the use of steel fibers in members subjected to dynamic loading lead to better performance.
This study presents an experimental investigation performed to investigate the using of steel fiber reinforced concrete (SFRC) as an alternative to negative reinforcement in continuous RC thin slab panels. More rational way has been used by replacing negative reinforcement near interior supports by steel fiber reinforced concrete (SFRC). Tests were carried out on four slab panels, simply supported under single point loading. One of which were made fully with NSC, and the others were made partially with SFRC in negative moment zone. Experimental results show that the ultimate load capacity are increased (23% -58%) and the cracking loads are increased (25% -62.5%) for tested specimens strengthened with SFRC, in comparison with the reference specimens. Crack arrest mechanism of steel fibers limits crack propagation, improves the ultimate and tensile strength. So, more practical technique can be concluded from this study and employed in manufacturing of thin slabs.
The most concerning issue confronting the planet these days is the ascent in Carbon dioxide (CO2) levels to record levels. The cement industries are answerable to between 6-8 % of worldwide CO2 emitting. In construction sectors, researchers tried to contribute in decreasing of CO2 in atmosphere produced by industry and using that was released in air. Accelerated CO2 curing is one of the methods used to get benefit from CO2 in the air. In this paper, CO2 concentration in addition to pressure, relative humidity and period of curing all had a significant influence upon the features of Cement – Based Composites. Results showed that using CO2 curing with different and specific properties of fibers (types, quantities, circumstances and lengths) improved the most mechanical properties and enhanced durability such as: strength, stiffness, ductility, toughness, porosity, and absorption.
The aim of this study is to develop Lightweight self-compacting concrete (LWSCC) mixtures using locally sourced waste materials such as Expanded Polystyrene Beads (EPS) and Waste Plastic Fibers (WPFs) which are all available abundantly available in Republic of Iraq at little or no cost. The fresh, hardened and mechanical properties of these LWSCC were studied, followed by results analysis. Five different mixes of LWSCC were prepared in term of WPF content (0.25, 0.5, 0.75, 1.0, and 1.25 %), in addition to the control mix (R mix) and lightweight concrete (E mix) made of EPS content as a replacement of coarse aggregate. The study showed that the LWSCC produced with these waste materials were decreased the density (lightweight) of the concrete mixes as EPS tend to form more clumps, absorb water and make the mix dry. Therefore, concrete mixtures were adjusted accordingly to be able to offset the workability caused by the addition of EPS. The increase in WPF content decreased the workability due to clumping that occurred in the mixing phase. The analysis of mechanical properties of the LWSCFRC specimens revealed that there was not much improvement. While LWSCC with 100% of EPS replacement as coarse aggregates and 1.25% WPFs provides the best flexural toughness performance