Welding strength is very important in safe use of polypropylene sheets. The determination of welding parameters and design of the welding tool has an impact on the weld strength. The welding parameters can be determined experimentally. In this study, Charpy impact test is used to determine suitable welding parameters in welding of polypropylene sheets with FSW method. At the same time, the weld zone microstructure is examined and Shore hardness measurements are made. The impact tests were performed on samples cut from the welded sheets. The impact tests values and hardness values were presented graphically. According to the test results, some welded parts behaved similar to the matrix material. In some welding parameters, Charpy impact test values were obtained close to values of the main materials. The suitable welding parameters were determined for polypropylene sheets welding.
The article presents the results of research concerning the effect of anthracite dust with 10%, 20%, 30%, 40% and 50% content in composites with a polypropylene matrix on selected properties. Hardness was examined with the Shore’s D method; stiffness, tensile strength as well as (MFR) Melt Flow Rate and (MVR) Melt Volume Rate of the investigated material were evaluated; wettability of the obtained material was also determined. Surface and volume resistivity were also investigated; the thermal properties of the filler were determined by thermogravimetric analysis (TGA). It was found that the investigated polypropylene composites filled with anthracite dust are hydrophobic materials and the composite hardness and stiffness are growing along with the volumetric increase of anthracite. It was noted that anthracite reinforces the material to a limited extent.
Coal ash produced from thermal power plants as a substitute for conventional construction material has increased considerably in recent years. In the past, studies on partial replacement of soil were carried out with a single type of ash. Because of the insufficient evidence, limited research has been initiated on the productive usage of Fly and Bottom Ashes. This paper aims to study the properties of these materials and investigate their efficacy in road construction. Laboratory investigations were conducted to assess chemical and physical properties and mechanical performance to evaluate both ash types in pavement construction. The rutting factor is calculated for various combinations of coal ash materials with the addition of polypropylene fiber as a reinforcement in increments of 0.1% of its total weight with an aspect ratio of 200. The analytical tool ANSYS is used to validate the service life, vertical strain and quality of reinforced ash materials.
The durability characteristics of Engineered Cementitious Composites (ECC) with various fibers such as polypropylene and glass were investigated in view of developing composites with high resistance to cracking. ECC offer large potential for durable civil infrastructure due to their high tensile strain capacity and controlled micro-crack width. In this study, fibre volume fractions (0.5%, 1%, 1.5%, and 2%) of both polypropylene and glass fibers varied and durability measures such as a rapid chloride penetration test, sorptivity, water absorption, acid attack, and sulphate attack were measured. Increasing the fiber content up to 1.5% improved the durability properties of ECC. The test results indicate that the glass fiber-reinforced Engineered Cementitious Composites have better durability characteristics than polypropylene fiber-reinforced ECC.
Concrete is the most widely used construction material because of its specialty of being cast into any desired shape. The main requirements of earthquake resistant structures are good ductility and energy absorption capacity. Fiber reinforced concrete possesses high flexural and tensile strength, improved ductility, and high energy absorption over the conventional concrete in sustaining dynamic loads. The aim of this paper is to compare the properties of concrete beams in which three types of fibers are added individually. Steel fibers, polypropylene fibers and hybrid fibers were added to concrete in the weight ratio of four percentages in the preparation of four beam specimens. The fourth specimen did not contain fibers and acted as a control specimen. The dimensions of the beam specimens were 150 × 150 × 700 mm. The reinforced concrete beams of M30 grade concrete were prepared for casting and testing. Various parameters such as load carrying capacity, stiffness degradation, ductility characteristics and energy absorption capacity of FRC beams were compared with that of RC beams. The companion specimens were cast and tested to study strength properties and then the results were compared. All the beams were tested under three point bending under Universal Testing Machine (UTM). The results were evaluated with respect to modulus of elasticity, first crack load, ultimate load, and ultimate deflection. The test result shows that use of hybrid fiber improves the flexural performance of the reinforced concrete beams. The flexural behavior and stiffness of the tested beams were calculated, and compared with respect to their load carrying capacities. Comparison was also made with theoretical calculations in order to determine the load-deflection curves of the tested beams. Results of the experimental programme were compared with theoretical predictions. Based on the results of the experimental programme, it can be concluded that the addition of steel, polypropylene and hybrid fibers by 4% by weight of cement (but 2.14% by volume of cement) had the best effect on the stiffness and energy absorption capacity of the beams.
Synthetic polymer latexes, such as styrene–butadiene rubber (SBR) latex addition in Portland cement has gained wider acceptance in many applications in the construction industry. Polymer-modified cementitious systems seals the pores and micro cracks developed during hardening of the cement matrix, by dispersing a film of polymer phase throughout the concrete. A comprehensive set of experimental test were conducted for studying the compressive properties of SBR latex polymer with crimped polypropylene fibres at relative volume fractions of 0.1 and 0.3%. The results indicated that the addition of polypropylene fibre has little effect on the reduction in the workability of concrete composite containing fly ash and SBR Latex. Increase in polypropylene fibres upto 0.3% Vf showed increase in compressive strength upto 57.5 MPa. The SBR concrete without fibre showed an increase in strength upto 20% compared to plain concrete. Test results also indicated that the compressive strength was increased in SBR fibre concrete by means of an ordinary dry curing process than wet curing because of their excellent water retention due to polymer film formation around the cement grains. On the contrary the compressive strength reduces for SBR fibre concretes under wet curing compared to dry curing.
This study focuses to develop a new hybrid Engineered Cementitious Composite (ECC) and assesses the performance of a new hybrid ECC based on the steel short random fiber reinforcement. This hybrid ECC aims to improve the tensile strength of cementitious material and enhance better flexural performance in an RC beam. In this study, four different mixes have been investigated. ECC with Poly Vinyl Alcohol (PVA) fiber and PolyPropylene (PP) fiber of 2.0% volume fraction are the two Mono fiber mixes; ECC mix with PVA fiber of 0.65% volume fraction hybridized with steel fiber of 1.35% volume fraction, PP fiber of 0.65% volume fraction hybridized with steel of 1.35% volume fraction are the two additional different hybrid mixes. The material properties of mono fiber ECC with 2.0 % of PVA is kept as the reference mix in this study. The hybridization with fibers has a notable achievement on the uniaxial tensile strength, compressive strength, Young’s modulus, and flexural behavior in ECC layered RC beams. From the results, it has been observed that the mix with PVA fiber of 0.65% volume fraction hybrid with steel fiber of 1.35% volume fraction exhibitimprovements in tensile strength, flexural strength, andenergy absorption. ThePP fiber of 0.65% volume fraction hybridized with steel of 1.35% volume fraction mix has reasonable flexural performance and notable achievement in displacement ductility overthe reference mix.