Engineering and Technology Journal

Geopolymer is a binder material that was created as a result of efforts to decrease Portland cement's negative environmental effects.  Geopolymer concrete shares certain properties with ordinary concrete, including brittleness. Like ordinary concrete, geopolymer concrete, when exposed to stresses, cracks and fails under these stresses. The purpose of adding fibers to geopolymer concrete is to overcome the matrix's brittleness and enhance its strength (particularly flexural strength). This study used metakaolin, a range of alkaline activators, and different quantities of polypropylene fibers to produce geopolymer concrete. Metakaolin's chemical composition, workability, density, flexural and compressive strength of geopolymer concrete were all examined for the purpose of determining the effect of polypropylene fibers on geopolymer concrete. Polypropylene fibers were used to make the mixes, which were then added to the mix at various percentages of 0 %, 0.5 %, and 1 % of the total volume of concrete. The results of the experiments showed that increasing the polypropylene fiber content to 0.5 % boosts the compressive strength of geopolymer concrete. On the seventh day, the compressive strength increased to 21 %. The density of geopolymer concrete was increased by adding polypropylene fibers, and there was a decrease in the workability with different fiber ratios.

 This research had been done to investigate the effect of adding natural powder of Pistachio Shell to PMMA, which popularly used in denture applications. The powder added in different weights fraction (3%, 6%, 9%, and 12%), and different average particle size (53µm, 106 µm, 150 µm, and 212µm %), and studying Compression Strength, Surface Hardness, and Density properties. Hand Lay-Up represented the method used to prepare the specimens in this research. The results were statistically analyzed by SPSS (one-way ANOVA) to determine the mean value and showed a significant difference for each particle size. The highest value of compression strength and surface hardness of PMMA composite specimens happened at (9%wt.) of the filler particles. Also the results represented that the density values for the composite specimens are increased with increasing the weight fraction of the filler particles.

In the present study, composites were prepared by Hand lay-up molding. The composites constituents were epoxy resin as the matrix, 3% volume fractions of Glass Fibers (G.F) as re enforcement and 2%, 4%, 6% volume fraction of micro powder (Aluminum Oxide Al2O3, Silicon Oxide SiO2 and Titanium Oxide TiO2) as filler. Studied the, hardness test, flexural strength, density, water absorption measurements and tests were conducted to reveal their values for each type of composite material. The results showed that the non – reinforced epoxy have lower properties than nano composites material. Measured density results had show an incremental increase with volume fraction increase and water absorption, hardness, and flexural strength had show an incremental increase with volume fraction increase and with smaller particle size.

This research studies the effect of adding industrial wastes materials with
different percentages on the thermal and mechanical properties of clay
bricks . Different types of admixtures were used in this work, including
rubber cuttings, wood saw dust and barley reeds ash with ( 5%,10% 15%
,20% ) by weight of each one respectively. Thermal conductivity, specific heat
capacity, compressive strength, flexural tensile strength, porosity and variation
of density have been examined for each samples at all percent of addition
and comparing with the reference clay bricks samples . Test results show that
the admixtures effect on the properties of clay bricks, when used barley reeds
ash which the best additives because take good properties, the density of clay
bricks is reduced 33%,thermal conductivity reduced 46% and the compressive
strength increased 20% comparing with the standard bricks. The experimental
work carried in the industrial factory of clay bricks in the Nahrawon city in
Baghdad.

The weather in Iraq is hot in summer and cold in winter. Therefore , the
thermal insulation is of the main problems facing the engineers working in
building and housing sector
The paper presents an experimental investigation, It includes preparation of
several concrete mixes using lightweight aggregate (siporex and porcelinite &
suwdast ) to obtain light weight concrete of two densities ranging from (350-880
kg/m3), which provides a good thermal insulation. Based on the analysis of
experimental results several graphs and Tables have been prepared and presented
which can be used in the mix design of similar siporex concrete of densities from
(350-880 kg/m3) . The physical properties of siporex concrete , have been found
which included density (765-822kg/m3) , compressive strength (1.51-2.2 N/mm2)
& (2.8-3.7 N/mm2) ,thermal conductivity ( 0.19-0.39 W/M.K) for the two groups
respectively.