Advanced Concrete Technology

Present paper emphasizes on the strength properties of concrete using waste engine oil as admixture. Investigation has been carried out for evaluating the workability and strength properties of concrete using waste engine oil as admixture into the concrete structure. This has a positive environmental effect as the cost of safe disposal of waste industrial material is significantly higher and there are strict environmental regulations. The objective to evaluate the effect of used engine oil on properties of fresh and hardened concrete. However, tests considered for study are slump test and compressive strength test. Four different percentages of admixtures (used engine oil) are chosen in the experimentation at 0.6%, 0.8%, 1.0% and 1.2% by weight of cement. Finally it was concluded that workability was enhanced. Compressive strength of concrete was decreased with increase of waste engine oil into the composition. In order to improve the workability of concrete composition, waste engine oil is a good admixture in composition.

This paper investigates on analyzing the effects of use of Polypropylene fiber in the mechanical properties of concrete. One of the main tasks of the construction industry is to increase the strength and reliability of structures while reducing construction costs. Effective use of fiber reinforced concrete is likely to lead to reduction in reinforcement. Three mixes used polypropylene fiber with content 1.0%, 1.5%, and 2.0% percent. To provide a basis for comparison, reference specimens were cast without polypropylene fiber. The test results showed that the increase of mechanical properties (compressive strength) resulting from added of polypropylene fiber was relatively high.

Cement-based materials have complex multi-component, multiscale structures that first form through chemical reaction and then continue to change with time. As with most classes of materials, the porosity of cement paste strongly influ- ences its properties, including strength, shrinkage, creep, permeability and diffusion. Pores in cement paste range in size from nanometers to millimeters, and numerous investigations and models have

The durability performance of palm oil fuel ash engineered alkali-activated cementitious composite (POFA-EACC) mortar exposed to different acid solutions is assessed in this study. 50 mm cubic specimens used for the study were prepared from 100% POFA, alkali-activator (Na 2 SiO 3(aq) /NaOH (aq)) ratios of 2.5, different molarities (10, 12 and 14 M) of NaOH (aq) and 2% volume fraction of polyvinyl alcohol (PVA) fibres. Specimens were exposed to 10% H 2 SO 4(aq) , 10% HNO 3(aq) and 10% HCl (aq) at pH of 0.56, 0.52 and 0.42 respectively for 3, 6 and 9 months, with unexposed specimens as control. Small changes in compressive strength were identified with POFA mortar specimens during exposure to H 2 SO 4(aq) , while exposure to HNO 3(aq) and HCl (aq) greatly reduced the strength of the POFA mortar specimens. The results were supported through microstructural examinations using SEM, while the characterization was done using XRD and FTIR. The high resistance of POFA-EACC mortar to H 2 SO 4...

Received 3 May 2006, accepted 11 August 2006 Abstract This paper presents an investigation on the flexural behaviour of reinforced concrete beams produced from oil palm shell (OPS) aggregates. Utilising OPS in concrete production not only solves the problem of disposing ...

This paper is on modeling and measuring fiber-bridging constitutive law of Engineered Cementitious Composites (ECC), a high performance fiber-reinforced cementitious composite featuring high tensile ductility. Fiber-bridging constitutive law plays an ...

This paper investigates on analyzing the effects of use of Polypropylene fiber in the mechanical properties of cement mortar. An experimental study was conducted on the cement mortar reinforced by the different percentages of polypropylene fibre (0, 0.5,1 & 1.5%). The essential objective of this work is to study the mechanical properties of cement mortar containing different percentages of polypropylene fiber. Different tests have been done to determine some aspects namely the flow table test and compressive strength at age of curing 28 days was conducted on reference and polypropylene fiber reinforced mortar specimens. The results show that the use of polypropylene fiber gives an unambiguous improvement in these properties and thus the optimum percentages for this fiber have been taken into consideration. The results show a significant increasing in compressive strength with the increment of fibers content in cement mortar.

Greater confinement of the soil foundation may globally reduce the shear span length, which may raise the risk of shear failure of RC piles. On the other hand, soil confinement may improve the flexural ductility of the pile section locally. This study discusses these global and local impacts of soil confinement on the RC-pile mechanistic behaviors, experimentally and analytically. Small-scale mortar-based piles were newly produced as a mockup of real-scale reinforced concrete so as to obtain the consistent nominal shear strength by reducing the shear transfer along cracks to overcome the size effect. Then, the global impact of soil confinement on pile shear failure is reproduced inside the small-scale experimental devices with soil. The soil-pile interaction test also shows the local impact of soil confinement in terms of increasing the flexural ductility of the miniature pile section by suppressing cover spalling and local buckling of reinforcement. It is confirmed that the coupled...

Sustainability and material use have been becoming increasingly important in industry and academia in recent years. The investigation reported in this paper is carried out to study the feasibility of using crushed brick to substitute the coarse aggregate in concrete, replacing stone aggregate (partly) by crashed brick. the target compressive strength of stone aggregate concrete was 34 MPa remaining concretes were made by replacing the stone aggregate (partly) by equal volume of brick aggregate while everything else was kept unchanged. The only variable considered in this study was the volumetric replacement (0%, 25%, 50, and 75%) of stone aggregate by brick aggregate. Crashed Brick materials are a great prospective material for aggregate replacement due to their desirable mechanical properties and availability in waste streams worldwide. A total of 4 numbers of concrete mixes specimens are casted with and without crushed bricks and tested under compression relevant to British standard specifications. Test results indicated that using crushed bricks reduces the strength of concrete. Also, the percentage of water to cement ratio increases for constant slump when the percentage of crushed bricks increased.

In this paper, the use of river aggregates for making pervious concrete was studied. Pervious concrete is a concrete which consists of coarse aggregate and cement paste without fine aggregate it's studied in this research. River aggregates used in manufacturing of pervious concrete have remarkable bearing on compressive strength and permeability of pervious concrete. The properties of pervious concrete is determined by conducting laboratory experiments on mixes of pervious concrete prepared using river aggregate with water cement ratio 0.35% for mix design purposes. The objective of this investigation is to study the effect of river aggregate on pervious concrete. This paper gives the results about the properties like density, compressive strength and permeability and void ratio of pervious concrete. The results indicate that river aggregate can be used as coarse aggregates for making pervious concrete with acceptable properties.

Recently, Prestressed Reinforced Concrete (PRC) has been accepted as a reasonable structural member that permits cracking. A PRC member is a visible design alternative to either reinforced concrete (RC) or fully prestressed concrete (PC). In Japan, PRC has been widely used for bridge structures because it is economical. PRC members are generally designed to allow cracking under full service loads. Flexural cracking in PRC beams has been already studied and the flexural crack width can be accurately predicated by equations available in the present codes (ACI, CEB-FIP, JSCE, etc.). On the other hand, shear cracking behavior in PRC members is barely understood. The objective of the present study is, therefore, to experimentally explore the shear cracking behavior of PRC beams. Three I-shaped RC and four I-shaped PRC beams were tested under four-point monotonic loading. The experimental program was carried out focusing on the influence of prestressing force, side concrete cover, stirrup...