Concrete Composites

The purpose of this work is to physically characterize wood-cement composite materials. The wood species used are Ayous, Movingui, African Padouk and Sapelli. The cement used is Portland cement CPJ35. For that purpose, we made specimens with wood species cited above. Then we carried out the drying and the humidification of these samples and made necessary measurements to characterize these materials physically. We determined most important physical properties of wood (density, the total volume shrinkage and swelling, moisture content and specific gravity) to characterize these materials. It comes out from this study that wood-cement composite materials are lighter than usual building materials such as mortar and concrete. We noted that, of four wood-composite materials elaborated, the sapelli-cement composite is that which presents the best physical properties, in particular the hygroscopic properties.

One type of a new product for the usefulness of panel wall material containing mixed composite of cement, sand and recycle paper called as Paper Fiber Reinforced Foam Concrete (PFRFC) as upon of the reinforcement addition is expected can improve materials quality for non load bearing wall. Pursuant to study of paper fiber in mixture of concrete it was produce a strong structure materials, environmental friendly and economical. By that, this study have practiced using paper fiber with other mixture of lightweight foamed concrete to search out the good material for lightweight concrete in term of the tension strength, compression strength and absorption of noise. Paper fiber come from wood fiber which have experienced of crushing process, condensation, and pickling have idiosyncrasy in absorbent strength of sound and strength of tension but it is sensitive to water, slow harden and increase the density of foam concrete specimens. Experimental work of PFRFC have been conducted in the form of prism specimen, panel wall and cube, with water ratio, cement, and sand is 0.45 : 1 : 1.5 and mixed with 5%, 10%, 15% and 20% of paper fiber. The research ve shows that with addition of paper fiber, the flexural strength of the Paper Fiber Reinforced Foam Concrete (PFRFC) is increases although the compression strength of PFRFC is not as good as the flexural strength. The strength of wall panel of PFRFC is better compared to Normal Foam Concrete (NFC) wall panel in terms of the flexural strength and noise absorption. The density discovered is less than normal concrete density, which are 2400 kg/m3. The PFRFC density is appropriate for the lightweight material for wall panel, which is the range of density, are 800 - 900 kg/m3 for the specimen of PFRFC cube.

This paper introduces the potential use of recycled coarse aggregates (RCA) as natural coarse aggregates replacement in concrete design. RCA is obtained from the demolition and waste of old building. RCA is suggested to be used as substitution for natural coarse aggregates in new concrete mixture in order to reduce the consumption of natural resources. In the pass research towards RCA suggested that by replacing natural coarse aggregates by RCA can be more environmental friendly and reducing the consumption of natural resources. This paper will be pointed on the further study on the various relative range of RCA replacement in concrete design. In this study, the percentage of replacement is undertaken by specimens 0% (control specimens), 15%, 30%, 60% and 80% by weight. Compressive strength test, flexural strength test, density test, ultrasonic pulse velocity test will be carried according to British Standards.

This paper discusses the structural behaviour of latex modified ferrocement in comparison with conventional ferrocement particularly when exposed to severe environmental conditions. The development of strength, deformability and fracture properties were slightly different from conventional ferrocement. Test result indicates a significant improvement in reducing and bridging micro cracks, especially in the prepeak load region. Fracture toughness and deformability increased significantly. However, the post peak behaviour was quite similar to conventional ferrocement.

More than 80% of roadway mileage in the world carries less than 400 vehicles per day and these roads are classified as low volume roads. India has essentially a rural oriented economy with 72% of its population living in villages. The low volume roads are part of tertiary road system, which consists of other district roads and village roads. The traffic conditions on these roads are distinctly different from the major roads. A variety of vehicles are used for transportation of goods on rural roads, ranging from bullock-carts to the fast moving commercial vehicles. Permanent deformation of the unbound base and sub-base layer is one of the distress types on these roads that require extensive maintenance. The gradation is the most important property that an aggregate can contribute to the performance of pavement. In the present study, an attempt has been made to investigate the rutting potential of low volume roads, taking into account base course gradation, sub-base course gradation, sub-base field density, subgrade field density, subgrade moisture content, subgrade California Bearing Ratio, and traffic volume. The influence of these factors on the rutting potential of in-service pavements has been investigated and a response type model has been developed.

The present work deals with the results of experimental investigations on steel fiber reinforced self compacting concrete. Effects of these fibers on various strengths of concrete were studied with varied fiber content from 0.5 to 3% at a specific interval with weight of cement. Strengths considered for investigation were compressive strength, flexural strength, split tensile and bond strength and tests on fresh concrete were also conducted. Ductility of concrete is found to increase in the fiber reinforced self compacting concrete as observed from the load deflection study. The Poisson’s ratio is found to vary within the specified limits with static modulus of concrete relation between flexural shear strength and all other strengths are developed. A comparison result of steel fiber reinforced self compacting concrete and that of normal self compacting concrete shows the significant improvement in the results of various strengths.

There are many ways to minimize the failure of the structures made up of reinforced concrete. The custom approach is to adhesively bond fiber polymer Composite on to the structure. This also helps to increase the toughness and tensile strength & to improve the cracking & deformation characteristic of the resultant composite. But this method adds another layer, which is prone to degradation, when exposed to marine environment due to surface blistering. As a result adhesive bond strength is reduced, which results in the de-lamination of composite. So, the approach is to use fibers in concrete known as FRC. This method of reinforcing the concrete substantially alters the properties of non-reinforced cement based matrix which is brittle in nature, possesses little tensile strength compared to the inherent. Compressive strength.

Tensile stresses on concrete leading to the formation of cracks which further leads to the spalling of concrete. To overcome this shortcoming, due to its high tensile strength, ductility, ability to arrest propagation of cracks, improved bond strength, etc. This paper investigates the different strengths of Steel Fiber Reinforced Concrete (SFRC) using Fly ash as cement replacement. Silica fume and fly ash are the by-products and so has the uncontrolled engineering properties which sometimes don’t give the required results. The objective of this paper is to study the behavior of fly ash concrete with steel fibers under shear and torsion.

Composites are finding increased use in structural applications, in particular for aerospace and automotive purposes. Fiber reinforced composite possess high strength and stiffness. Some of these materials perform equally well or better than many traditional metallic materials. In addition, fatigue strength-to-weight ratios as well as fatigue damage tolerance of many composite laminates are excellent. To analyze metallic structures, properties of metals are easily available, but for composite structures properties of composite material are not readily available. Composite material is nothing but a laminate made from number of different lamina, and the properties of laminate depends on properties of lamina. The material properties of composite are required for carrying out stress analysis and fatigue analysis which in turn predicts the life of component. Objective of present work is to study the behavior of composite materials. This investigation deals with lamina composed of polymer matrix and carbon fibers. The aim of this study is to determine following properties. • Elastic properties, thermal properties and strength properties of transversely isotropic lamina by all methods of Micromechanics. • Properties of orthotropic lamina using Method of Cells. • Verifying the results predicted by Method of Cells with the other micromechanics methods like Composite Cylinder Assemblages (CCA) method, Rule of Mixture, Halpin-Tsai, Chamis method and Zing-ming Huang method.

In this modern age, civil engineering constructions have their own structural and durability requirements. Fiber Reinforced Concrete (FRC) is a composite material made primarily from hydraulic cements, aggregates and discrete reinforcing fibers. Fiber incorporation in concrete, mortar and cement paste enhances many of the engineering properties of these materials such as fracture toughness, flexural strength, resistance to fatigue, impact, thermal shock and spalling. The SFRC is a composite material made of cement, fine and coarse aggregates and discontinuous discrete steel fibers. Recently developed an analytical model to predict the shear, torsional strength and bending torsion behavior of fiber reinforced concrete beam with experimental substantiation. However, very little work has been reported in combined torsion and shear. Similarly to beam with conversional reinforcement, the presence of shear may significance influence on torsional strength of fiber concrete beams. Present investigate the mechanical properties like as shear strength, and torsion strength of concrete with different types of steel fiber with constant volume fractions and different aspect ratio.