The presence of construction wastes such as clay bricks, glass, wood, plastic, and others in large quantities causes serious environmental problems in the world. Where these wastes can be used to preserve the natural resources used in construction and reduce the impact of this problem on the environment, it also works to reduce the problem of high loads of concrete blocks. Clay bricks aggregate (AB) can be recycled as coarse aggregate and replaced with volumetric proportions of coarse aggregate by ( 5% and 10%), as well as the use of clay brick powder (PB) by replacing its weight of cement (5% and 10%) and reduced in the manufacture of concrete blocks (blocks). Four mixtures will be prepared and tested to learn how to reuse the brick coarse aggregate ACB and PB powder brick as substitute materials for producing concrete blocks, use the water spray method to treat concrete building blocks (blocks) and check the Dimensions and compressive strength, and absorption.
Self-compacted concrete (SCC) is a highly flowable concrete, with no segregation which can be spread into place by filling the structures framework and permeate the reinforcement without any compaction or mechanical consolidation ACI 237R-14. One of the most important problems faced by concrete industry in Iraq and Gulf Arab land is deterioration due to internal sulfate attack (ISA) that causes damage of concrete and consequently reduces its compressive strength, increases expansion and may lead to its cracking and destruction. The experimental program was focused to study two ordinary Portland cements with different chemical composition with (5, 10 and 15) % percentage of high reactivity metakaoline (HRM)
... Show MoreThis paper demonstrates an experimental and numerical study aimed to compare the influence of openings of different configurations on the flexural behavior of prestressed concrete rafters. The experimental program consisted of testing six simply supported prestressed concrete rafters; 5 rafters are perforated, and the other one is solid as a reference. All rafters were tested under monotonic midpoint load. The variable which has been investigated in this work was the opening’s configuration (quadrilateral or circular) with the same upper and lower chords depths. The results indicate improvement in the beam flexural behavior using the circular openings compared to the quadrilateral o
One of the most important problems that faces the concrete industry in Iraq is the deterioration due to internal sulfate attack , since it reduces the compressive strength and increases the expansion of concrete. Consequently, the concrete structure may be damage .The effects of total and total effective sulfate contents on high strength concrete (HSC) have been studied in the present study. The research studied the effect of sulfate content in cement , sand and gravel , as well as comparing the total sulfate content with the total effective SO3 content. Materials used were divided into two groups of SO3 in cement ,three groups of SO3 in sand ,and two groups of SO3 in gravel. The results show that considering the total effective sulfate con
... Show MoreThe present investigation considers the effect of curing temperatures (30, 40, and 50˚C) and curing compound method on compressive strength development of high performance concrete, and compares the results with concrete cured at standard conditions and curing temperature (21˚C). The experimental results showed that at early ages, the rate of strength development at high curing temperature is greater than at lower curing temperature, the maximum increasing percentage in compressive strength is 10.83% at 50C˚ compared with 21C˚ in 7days curing age. However, at later ages, the strength achieved at higher curing temperature has been less, and the maximum percentage of reduction has been 5.70% at curing temperature 50C˚ compared with 21
... Show MoreAs an alternative to Ordinary Portland Cement (OPC), the alkali-activated binders have been developed with better technical characteristics and more extended durability. The Alkali-Activated Iraqi Natural Pozzolans (AANP) could produce geopolymer cementation building materials and make them ecologically acceptable. The primary advantage of geopolymer cement is that it has a lower environmental effect that contributes to it. The engineering characteristics of geopolymer concrete produced using activated Iraqi natural Pozzolan are summarized in this research. The mechanical properties, modulus of elasticity, and ultrasonic pulse velocity of various concrete mixes were determined via exp
Despite widespread agreement on the beneficial nature of hydrated lime (HL) addition to asphalt concrete mixes, understanding of the effect of HL particle size is still limited. Previous investigations have focused mainly on two different size comparisons, and so certain guidance for a practical application cannot yet be produced. This study investigates three distinct sizes of HL, in the range of regular, nano, and sub-nano scales, for their effects on the properties of modified asphalt concretes. Five different percentages of HL as a partial replacement of ordinary limestone filler in asphalt concrete mixes were studied for wearing course application purposes. Experimental tests were conducted to evaluate the mechanical properties
... Show MoreApplying load to a structural member may result in a bottle-shaped compression field especially when the width of the loading is less than the width of bearing concrete members. At the Building and Construction Department – the University of Technology-Iraq, series tests on fibre reinforced concrete specimens were carried out, subjected to compression forces at the top and bottom of the specimens to produce compression field. The effects of steel fibre content, concrete compressive strength, transverse tension reinforcement, the height of test specimen, and the ratio of the width of loading plate to specimen width were studied by testing a total of tenth normal strength concrete blocks with steel fibre and one normal s
... Show MoreThe performance of flexible pavements is significantly impacted by the permanent deformation (rutting) of asphalt pavements. Rutting shortens the pavement's useful service life and poses significant risks to those using the highway since it alters vehicle handling characteristics.. The aim of this research is to evaluate the permanent deformation of asphalt mixtures under different conditions,to achieve this aim 108 cylindrical specimens has been prepared and tested under repeated loading in uniaxial compression mode. Five factors were considered in this research, these factors represent the effect of environmental condition and traffic loading as well as mixture properties, they include testing temperature, loading condition (stress level
... Show MoreAs an alternative to Ordinary Portland Cement (OPC), the alkali-activated binders have been developed with better technical characteristics and more extended durability. The Alkali-Activated Iraqi Natural Pozzolans (AANP) could produce geopolymer cementation building materials and make them ecologically acceptable. The primary advantage of geopolymer cement is that it has a lower environmental effect that contributes to it. The engineering characteristics of geopolymer concrete produced using activated Iraqi natural Pozzolan are summarized in this research. The mechanical properties, modulus of elasticity, and ultrasonic pulse velocity of various concrete mixes were determined via experimental study. The impact of essential variables like w
... Show MoreBackground: Fluoridated acrylic resin material can present more stable properties when compared with conventional one.The most widely used fluoride –containing substance added to dental resin materials is sodium fluoride (Naf). This study evaluated the effect of Naf in different concentration to the acrylic resin denture base material and its effect on tensile strength ,modules of elasticity with long –term water immersion (after 4 months immersion in de-ionized water) Materials and methods: Eighty specimens from dumbbells shaped metal pattern for tensile strength test were preparedaccording to ISO 527: 1993 plastic –Determination tensile properties ,in dimensions(60mm, 12mm, 3 ± 0.2mm) length, width and depth respec
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