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Papers by Doha M Al Saffar
Effect of internal curing on behavior of high performance concrete: An overview, 2019
This study reviews research experiences on developing an internal curing approach for high-perfor... more This study reviews research experiences on developing an internal curing approach for
high-performance concrete (HPC). Common materials have been used to produce the
internal curing required to reduce self-desiccation in cement paste and will subsequently
reduce the risks of developing cracks in hardened concrete. Furthermore, this study focuses
on the behavior of HPC, including density, strength (compressive, splitting tensile, and
flexural), shrinkage (autogenous and drying), and microstructure of hydrated cement paste.
Results indicate that internal curing is more effective at a later age on splitting tensile and
flexural strength than on compressive strength. Internal curing has enabled the interfacial
transition zone increasingly compact and dense, thereby enhancing strength.
www.sciencepubco, 2018
Solid generation has brought about numerous natural issues, for example, CO2 discharge. An option... more Solid generation has brought about numerous natural issues, for example, CO2 discharge. An option eco-accommodating concrete,
known as green cement, ought to be investigated. Squander materials from marine waste, ventures, and farming can be reused to deliver
green cement. This paper displays a survey of ongoing advancement identified with the attainability of utilizing stoneware earth in solid
blend. The report centers around the likelihood of using dirt block squander as fractional substitution for Portland bond in cement and the
properties of crisp and solidified concrete, for example, usefulness, thickness, quality, and microstructure. This paper ought to give new
data on the uses of greener and supportable stoneware mud concrete. Past investigations showed that the ideal rate for supplanting Port-
land concrete with earthenware dirt ran somewhere in the range of 10wt% and 30wt%.
IJERA publisher, 2017
The Ultra- Fine Glass Powder (UFGP) smaller than 0.075 mm (No. 200) produced from grinding and po... more The Ultra- Fine Glass Powder (UFGP) smaller than 0.075 mm (No. 200) produced from grinding and polishing edges on flat glass of different size and thickness, has been used instead of sand in different proportions which are 15%, 30%, 45%, 60%, 75%, 90% and 100%. It was found that there was a slight decrease in workability when the percentage of replacement decreased.The effects of UFGP on properties ofhardened concrete which includedry density, water absorption compressive strength and thermal conductivity are analyzed. The results of this study show that UFGP is determined to have a significant effect on increasing its compressive strength at 15%, 30%, and 45% , and there is a reductionindry density atup to ~ 45% . As for cost analysis and thermal conductivity test, this investigation is an environmental one by taking into consideration the fact that UFGP could be used to produce lightweight aggregate concrete without the need for high cost or energyloss.
The main objective of this work is to study the effect of adding plastic fibers on Lightweight Ag... more The main objective of this work is to study the effect of adding plastic fibers on Lightweight Aggregate Foamed Concrete (LWAFC) using mix proportion of 1:2.6:0.4 by volume (cement: fine Porcelanite: coarse Porcelanite) with 2% foaming agent by weight of water, and using sand as a partial and total replacement of local Porcelanite aggregate in that mix. The properties of lightweight aggregate foamed concrete reinforced with different percentages of plastic fiber (0.5, 0.75, and 1% by volume) were studied. Compressive strength, splitting tensile strength, flexural strength, dry density, initial surface absorption, water absorption, ultrasonic pulse velocity, acoustic impedance, and impact resistance tests were conducted on mixes at ages of 7, 28, and 60 days. The results showed a significant increasing in impact resistance, splitting tensile strength, and water absorption 34.55%, 4.2%, 326%, and 27.3% respectively. While the results indicated that the compressive strength, ultrasonic pulse velocity, dry density and acoustic impedance of the composites were reduced when the crimped plastic fiber volume fraction increases. The percentage of reduction of these properties was 15%, 11.1%, 6.23%, and 12.55% respectively.
— This paper reports about the use of recycled iron powder (IP) in producing cement mortar under ... more — This paper reports about the use of recycled iron powder (IP) in producing cement mortar under normal conditions. Flow table test was performed on fresh mortar. Destructive tests were conducted on cubes of the hardened mortar to obtain the compressive and flexural strengths of the cement mortar. The effects of adding 10%, 20%, 30%, and 40% of waste IP as a natural sand replacement were assessed and compared. Waste iron are of two types: iron IP, which shows a similar particle size distribution to that of the sand used in making the samples, and fine iron powder (FIP), which contains fine particles. The compressive strength decreased with the increased amount of added IP in the mixtures, but it increased with the addition of 10% FIP and decreased gradually with the increased FIP level. By contrast, the flexural strength significantly increased with increased FIP in the mixtures. Recommendations regarding the applications of recycling to conserve resources and raw materials and prevent environmental pollution are provided.
This paper reported an investigation on six mixes of Lightweight Aggregate Concrete (LWAC) were p... more This paper reported an investigation on six mixes of Lightweight Aggregate Concrete (LWAC) were produced to study the effect of elevated temperature (200 to 700˚C) on the residual mechanical properties. The first three mixes were considered as reference mixes consisting of cement, Porcelanite as coarse aggregate, and fine Porcelanite as a partial replacement and total replacement of sand. Two percent of foam agent by weight of water was added to produce Lightweight Aggregate Foamed Concrete (LWAFC). The results of testing showed that the high elevated temperatures resistance of foamed concrete is better in terms of the proportional loss in strength than normal concrete. Also, the mechanical properties of LWAFC containing 50% and 100% of fine Porcelanite aggregate are less affected by high temperature than the sanded LWAFC.
The Ultra-Fine Glass Powder (UFGP) smaller than 0.075 mm (No. 200) produced from grinding and pol... more The Ultra-Fine Glass Powder (UFGP) smaller than 0.075 mm (No. 200) produced from grinding and polishing edges on flat glass of different size and thickness, has been used instead of sand in different proportions which are 15%, 30%, 45%, 60%, 75%, 90% and 100%. It was found that there was a slight decrease in workability when the percentage of replacement decreased.The effects of UFGP on properties ofhardened concrete which includedry density, water absorption compressive strength and thermal conductivity are analyzed. The results of this study show that UFGP is determined to have a significant effect on increasing its compressive strength at 15%, 30%, and 45% , and there is a reductionindry density atup to ~ 45%. As for cost analysis and thermal conductivity test, this investigation is an environmental one by taking into consideration the fact that UFGP could be used to produce lightweight aggregate concrete without the need for high cost or energyloss.
Effect of internal curing on behavior of high performance concrete: An overview, 2019
This study reviews research experiences on developing an internal curing approach for high-perfor... more This study reviews research experiences on developing an internal curing approach for
high-performance concrete (HPC). Common materials have been used to produce the
internal curing required to reduce self-desiccation in cement paste and will subsequently
reduce the risks of developing cracks in hardened concrete. Furthermore, this study focuses
on the behavior of HPC, including density, strength (compressive, splitting tensile, and
flexural), shrinkage (autogenous and drying), and microstructure of hydrated cement paste.
Results indicate that internal curing is more effective at a later age on splitting tensile and
flexural strength than on compressive strength. Internal curing has enabled the interfacial
transition zone increasingly compact and dense, thereby enhancing strength.
www.sciencepubco, 2018
Solid generation has brought about numerous natural issues, for example, CO2 discharge. An option... more Solid generation has brought about numerous natural issues, for example, CO2 discharge. An option eco-accommodating concrete,
known as green cement, ought to be investigated. Squander materials from marine waste, ventures, and farming can be reused to deliver
green cement. This paper displays a survey of ongoing advancement identified with the attainability of utilizing stoneware earth in solid
blend. The report centers around the likelihood of using dirt block squander as fractional substitution for Portland bond in cement and the
properties of crisp and solidified concrete, for example, usefulness, thickness, quality, and microstructure. This paper ought to give new
data on the uses of greener and supportable stoneware mud concrete. Past investigations showed that the ideal rate for supplanting Port-
land concrete with earthenware dirt ran somewhere in the range of 10wt% and 30wt%.
IJERA publisher, 2017
The Ultra- Fine Glass Powder (UFGP) smaller than 0.075 mm (No. 200) produced from grinding and po... more The Ultra- Fine Glass Powder (UFGP) smaller than 0.075 mm (No. 200) produced from grinding and polishing edges on flat glass of different size and thickness, has been used instead of sand in different proportions which are 15%, 30%, 45%, 60%, 75%, 90% and 100%. It was found that there was a slight decrease in workability when the percentage of replacement decreased.The effects of UFGP on properties ofhardened concrete which includedry density, water absorption compressive strength and thermal conductivity are analyzed. The results of this study show that UFGP is determined to have a significant effect on increasing its compressive strength at 15%, 30%, and 45% , and there is a reductionindry density atup to ~ 45% . As for cost analysis and thermal conductivity test, this investigation is an environmental one by taking into consideration the fact that UFGP could be used to produce lightweight aggregate concrete without the need for high cost or energyloss.
The main objective of this work is to study the effect of adding plastic fibers on Lightweight Ag... more The main objective of this work is to study the effect of adding plastic fibers on Lightweight Aggregate Foamed Concrete (LWAFC) using mix proportion of 1:2.6:0.4 by volume (cement: fine Porcelanite: coarse Porcelanite) with 2% foaming agent by weight of water, and using sand as a partial and total replacement of local Porcelanite aggregate in that mix. The properties of lightweight aggregate foamed concrete reinforced with different percentages of plastic fiber (0.5, 0.75, and 1% by volume) were studied. Compressive strength, splitting tensile strength, flexural strength, dry density, initial surface absorption, water absorption, ultrasonic pulse velocity, acoustic impedance, and impact resistance tests were conducted on mixes at ages of 7, 28, and 60 days. The results showed a significant increasing in impact resistance, splitting tensile strength, and water absorption 34.55%, 4.2%, 326%, and 27.3% respectively. While the results indicated that the compressive strength, ultrasonic pulse velocity, dry density and acoustic impedance of the composites were reduced when the crimped plastic fiber volume fraction increases. The percentage of reduction of these properties was 15%, 11.1%, 6.23%, and 12.55% respectively.
— This paper reports about the use of recycled iron powder (IP) in producing cement mortar under ... more — This paper reports about the use of recycled iron powder (IP) in producing cement mortar under normal conditions. Flow table test was performed on fresh mortar. Destructive tests were conducted on cubes of the hardened mortar to obtain the compressive and flexural strengths of the cement mortar. The effects of adding 10%, 20%, 30%, and 40% of waste IP as a natural sand replacement were assessed and compared. Waste iron are of two types: iron IP, which shows a similar particle size distribution to that of the sand used in making the samples, and fine iron powder (FIP), which contains fine particles. The compressive strength decreased with the increased amount of added IP in the mixtures, but it increased with the addition of 10% FIP and decreased gradually with the increased FIP level. By contrast, the flexural strength significantly increased with increased FIP in the mixtures. Recommendations regarding the applications of recycling to conserve resources and raw materials and prevent environmental pollution are provided.
This paper reported an investigation on six mixes of Lightweight Aggregate Concrete (LWAC) were p... more This paper reported an investigation on six mixes of Lightweight Aggregate Concrete (LWAC) were produced to study the effect of elevated temperature (200 to 700˚C) on the residual mechanical properties. The first three mixes were considered as reference mixes consisting of cement, Porcelanite as coarse aggregate, and fine Porcelanite as a partial replacement and total replacement of sand. Two percent of foam agent by weight of water was added to produce Lightweight Aggregate Foamed Concrete (LWAFC). The results of testing showed that the high elevated temperatures resistance of foamed concrete is better in terms of the proportional loss in strength than normal concrete. Also, the mechanical properties of LWAFC containing 50% and 100% of fine Porcelanite aggregate are less affected by high temperature than the sanded LWAFC.
The Ultra-Fine Glass Powder (UFGP) smaller than 0.075 mm (No. 200) produced from grinding and pol... more The Ultra-Fine Glass Powder (UFGP) smaller than 0.075 mm (No. 200) produced from grinding and polishing edges on flat glass of different size and thickness, has been used instead of sand in different proportions which are 15%, 30%, 45%, 60%, 75%, 90% and 100%. It was found that there was a slight decrease in workability when the percentage of replacement decreased.The effects of UFGP on properties ofhardened concrete which includedry density, water absorption compressive strength and thermal conductivity are analyzed. The results of this study show that UFGP is determined to have a significant effect on increasing its compressive strength at 15%, 30%, and 45% , and there is a reductionindry density atup to ~ 45%. As for cost analysis and thermal conductivity test, this investigation is an environmental one by taking into consideration the fact that UFGP could be used to produce lightweight aggregate concrete without the need for high cost or energyloss.