Incorporation of Iraqi Rocks in the Production of Eco-Friendly Cement Mortar

2020 ◽  
Vol 38 (10A) ◽  
pp. 1522-1530
Author(s):  
Rawnaq S. Mahdi ◽  
Aseel B. AL-Zubidi ◽  
Hassan N. Hashim

This work reports on the incorporation of Flint and Kaolin rocks powders in the cement mortar in an attempt to improve its mechanical properties and produce an eco-friendly mortar. Flint and Kaolin powders are prepared by dry mechanical milling. The two powders are added separately to the mortars substituting cement partially. The two powders are found to improve the mechanical properties of the mortars. Hardness and compressive strength are found to increase with the increase of powders constituents in the cement mortars. In addition, the two powders affect water absorption and thermal conductivity of the mortar specimens which are desirable for construction applications. Kaolin is found to have a greater effect on the mechanical properties, water absorption, and thermal conductivity of the mortars than Flint. This behavior is discussed and analyzed based on the compositional and structural properties of the rocks powders.

2018 ◽  
Vol 777 ◽  
pp. 465-470
Author(s):  
Sutas Janbuala ◽  
Mana Eambua ◽  
Arpapan Satayavibul ◽  
Watcharakhon Nethan

The objective of this study was to recycle powdered marble dust to improve mechanical properties and thermal conductivity of lightweight clay bricks. Varying amounts of powdered marble dust (10, 20, 30, and 40 vol.%) were added to a lightweight clay brick at the firing temperatures of 900, 1000, and 1100 °C. When higher quantities of powdered marble dust were added, the values of porosity and water absorption increased while those of thermal conductivity and bulk density decreased. The decrease in apparent porosity and water absorption were also affected by the increase in firing temperature. The most desirable properties of the clay bricks were obtained for the powdered marble dust content of 40 vol.% and firing temperature 900 °C: bulk density of 1.20 g/cm3, compressive strength 9.2 MPa, thermal conductivity 0.32 W/m.K, and water absorption 22.5%.


2005 ◽  
Vol 287 ◽  
pp. 63-68 ◽  
Author(s):  
Jae Jun Kim ◽  
Sang Heum Youn ◽  
M.J. Cho ◽  
H.T. Shin ◽  
Jeong Bae Yoon ◽  
...  

To improve the mechanical properties of concretes containing recycled aggregates, pozzolanic materials were used to decrease the porosity of the recycled aggregates. These pozzolanic materials were adhered on the surface of recycled aggregates and closed the open pores so that the water absorption was decreased 1~2% as the amount of adsorption was increased. Compressive strength of cement mortars and concretes using surface treated recycled aggregates reaches above 95% of the strength of its natural counterparts. Investigation of the microstructures using the scanning electron micrographs showed the formation of dense interface after the adsorption treatment of pozzolanics to recycled aggregates.


2018 ◽  
Vol 27 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Jakub Jura ◽  
Małgorzata Ulewicz

The article presents the results of research aimed at using glass waste and ash from biomass. The tests were carried out for cement mortars samples with using glass cullet, ash from biomass and using both wastes in 50/50 proportions. The physical and mechanical properties of the standard mortar and modified mortars were tested. Standard mortar and cement mortar samples were made in which 10, 20 and 30% of the cement mass was used as part of the standard sand. The samples were made of CEM I 42.5R. Mortars containing fly ash addition had an increased compressive strength and a smaller drop in compressive strength after frost resistance tests than standard mortar. The use of glass cullet in the amount of up to 20% did not reveal any changes in the mechanical properties of mortars, but using them in a larger amount resulted in unfavorable results. The use of a mixture of these two waste materials did not improve the results. The research has shown the possibility of using this waste to modify cement mortars.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5275
Author(s):  
Dovilė Vasiliauskienė ◽  
Giedrius Balčiūnas ◽  
Renata Boris ◽  
Agnė Kairytė ◽  
Arūnas Kremensas ◽  
...  

In this study, tung tree and linseed drying oils, as well as semi-drying hempseed oil, were analyzed as the protective coatings for biocomposite boards (BcB) made of hemp shives, corn starch binder, and the performance-enhancing additives. The hydrophobization coatings were formed at 40, 90, and 120 °C temperatures, respectively. The physical-mechanical properties such as the compressive strength, thermal conductivity, dimensional stability, water absorption, and swelling were tested. In addition, scanning electron microscopy (SEM) was employed for the analysis of the board microstructure to visualize the oil fills and impregnation in pores and voids. It was demonstrated that the compressive strength of oil-modified BcBs compared to uncoated BcBs (at 10% of relative deformation) increased by up to 4.5-fold and could reach up to 14 MPa, water absorption decreased up to 4-fold (from 1.34 to 0.37 kg/m2), swelling decreased up to 48% (from 8.20% to 4.26%), whereas the thermal conductivity remained unchanged with the thermal conductivity coefficient of around 0.085 W/m·K. Significant performance-enhancing properties were obtained due to the formation of a protective oil film when the tung tree oil was used.


Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 113 ◽  
Author(s):  
Hongfang Sun ◽  
Li Ling ◽  
Zhili Ren ◽  
Shazim Ali Memon ◽  
Feng Xing

This paper evaluated the effect of graphene oxide/graphene (GO/GR) hybrid on mechanical properties of cement mortar. The underlying mechanism was also investigated. In the GO/GR hybrid, GO was expected to act as a dispersant for GR while GR was used as reinforcement in mortar due to its excellent mechanical properties. For the mortar specimen, flexural and compressive strength were measured at varied GO to GR ratios of 1:0, 3:1, 1:1, 1:3, and 0:1 by keeping the total amount of GO and GR constant. The underlying mechanism was investigated through the dispersibility of GR, heat releasing characteristics during hydration, and porosity of mortar. The results showed that GO/GR hybrid significantly enhanced the flexural and compressive strength of cement mortars. The flexural strength reached maximum at GO:GR = 1:1, where the enhancement level was up to 23.04% (28 days) when compared to mortar prepared with only GO, and up to 15.63% (7 days) when compared to mortar prepared with only GR. In terms of compressive strength, the enhancement level for GO:GR = 3:1 was up to 21.10% (3 days) when compared with that of mortar incorporating GO only. The enhancement in compressive strength with mortar at GO:GR = 1:1 was up to 14.69% (7-day) when compared with mortar incorporating GR only. In addition to dispersibility, the compressive strength was also influenced by other factors, such as the degree of hydration, porosity, and pore size distribution of mortar, which made the mortars perform best at different ages.


2005 ◽  
Vol 486-487 ◽  
pp. 305-308 ◽  
Author(s):  
Jae Jun Kim ◽  
Sang Heum Youn ◽  
M.J. Cho ◽  
H.T. Shin ◽  
Jeong Bae Yoon ◽  
...  

To improve the mechanical properties of concretes containing recycled aggregates, pozzolanic materials such as Silica Fume and Meta Kaolin were used to decrease the porosity of the recycled aggregates. These pozzolanic aterials were adhered on the surface of recycled aggregates and closed the open pores so that the water absorption was decreased 1~2% as the amount of adsorption was increased. Compressive strength of cement mortars and concretes using surface treated recycled aggregates reached above 95% of the strength of its natural counterparts. Investigation of the microstructures using the scanning lectron micrographs showed the formation of dense interface after the adsorption treatment of pozzolanics to recycled aggregates.


2021 ◽  
Vol 06 ◽  
Author(s):  
Ai Zhang ◽  
Yong Ge

Background: Buildings in high altitude region often face low pressure and low humidity service environment, which has a great impact on the mechanical properties and durability of cement-based materials. Objective: In this paper, the effects of nano-silica (NS) on the strength and water absorption of cement mortar exposed to the low pressure and low humidity environment were studied. Methods: Mechanical properties (compressive strength and flexural strength) and durability (water absorption) were measured. And the hydration degree of cement was tested to assist analysis. Results: The flexural strength of mortar decreased and the compressive strength increased slowly after 28 days of exposure under low pressure and low humidity environment. Especially, the introduction of 1% NS could reduce the compressive strength loss and flexural strength loss of mortar under low pressure and low humidity environment. It was also found that the water absorption of the mortar in low pressure and low humidity environment was related to the tortuous degree of the pores inside the specimen. Conclusion: The introduction of 1% NS contributed the most to the mechanical properties (compressive strength and flexural strength) and durability (water absorption) of cement mortar.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2986
Author(s):  
Nadezda Stevulova ◽  
Vojtech Vaclavik ◽  
Viola Hospodarova ◽  
Tomáš Dvorský

This paper aims to develop recycled fiber reinforced cement plaster mortar with a good workability of fresh mixture, and insulation, mechanical and adhesive properties of the final hardened product for indoor application. The effect of the incorporation of different portions of three types of cellulose fibers from waste paper recycling into cement mortar (cement/sand ratio of 1:3) on its properties of workability, as well as other physical and mechanical parameters, was studied. The waste paper fiber (WPF) samples were characterized by their different cellulose contents, degree of polymerization, and residues from paper-making. The cement to waste paper fiber mass ratios (C/WPF) ranged from 500:1 to 3:1, and significantly influenced the consistency, bulk density, thermal conductivity, water absorption behavior, and compressive and flexural strength of the fiber-cement mortars. The workability tests of the fiber-cement mortars containing less than 2% WPF achieved optimal properties corresponding to plastic mortars (140–200 mm). The development of dry bulk density and thermal conductivity values of 28-day hardened fiber-cement mortars was favorable with a declining C/WPF ratio, while increasing the fiber content in cement mortars led to a worsening of the water absorption behavior and a lower mechanical performance of the mortars. These key findings were related to a higher porosity and weaker adhesion of fibers and cement particles at the matrix-fiber interface. The adhesion ability of fiber-cement plastering mortar based on WPF samples with the highest cellulose content as a fine filler and two types of mixed hydraulic binder (cement with finely ground granulated blast furnace slag and natural limestone) on commonly used substrates, such as brick and aerated concrete blocks, was also investigated. The adhesive strength testing of these hardened fiber-cement plaster mortars on both substrates revealed lime-cement mortar to be more suitable for fine plaster. The different behavior of fiber-cement containing finely ground slag manifested in a greater depth of the plaster layer failure, crack formation, and in greater damage to the cohesion between the substrate and mortar for the observed time.


2010 ◽  
Vol 168-170 ◽  
pp. 190-194 ◽  
Author(s):  
Zhen Jun Wang ◽  
Rui Wang ◽  
Yu Bin Cheng

In this paper, styrene-butadiene polymer emulsion SD622S was adopted to modify cement mortar; mechanical properties of cement mortars were studied and microstructures was analyzed by means of Scanning Electron Microscope (SEM) and Specific Surface Area & Pore Distribution Analyzer. The results show that in contrast to ordinary cement mortar, if water to cement ratio (W/C) is constant, compressive strength of modified cement mortar can decrease, while flexural strength and toughness, ratio of compressive strength to flexural strength, increase with the increase of polymer to cement ratio in mass (P/C) at 7 and 28 curing days. With the increase of P/C, net structure made from polymer and cement hydration products is developed and pore whose size is smaller than 200Å begins to increase, which indicates pore diameters in modified cement mortar change to be finer. So microstructures of modified cement mortar become denser and display higher toughness.


Author(s):  
Apised Suwansaard

When polystyrene (PS) and hemp fiber waste were mixed into the sand aggregate, some physical-mechanical properties of mortar changed. The PS and hemp fiber were tested as partial replacements for sand in mortar with three designated percentages of 2.5, 5.0 and 10.0% by mass. The properties of mortar with PS were found to be better than that of the mortar with hemp fiber. The water absorption of mortar with PS was comparable with the reference mortar but lower than that of mortar with hemp fiber. The compressive strength of the mortar with PS was higher than that with hemp fiber whereas the tensile strength of the mortar with 2.5% PS and hemp fiber was comparable and was higher than that of the reference mortar. The thermal conductivity of a wall plastered by mortar containing PS decreased as the PS content was increased, whereas the thermal conductivity of a wall plastered by mortar containing hemp fiber increased as the hemp fiber content was increased. Thick crack was detected in the reference wall while hair line crack occurred from the wall plastered with PS and hemp fiber mortars. The results indicated that 10.0% PS could be used as a partial replacement for sand in mortar with an improvement in some of the properties of the mortar.


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