scholarly journals Influence of NaOH treatment of rubber aggregates on the durability properties of rubberized mortars

2021 ◽  
Vol 16 (2) ◽  
pp. 189-201
Author(s):  
Kechkar Chiraz ◽  
Benamara F. Zohra ◽  
Nigri Ghania ◽  
Hebhoub Houria ◽  
Cherait Yacine ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Mechanical Performance ◽  
Sodium Hydroxide Solution ◽  
Chemical Degradation ◽  
Substitution Rates ◽  
Flexural Tensile Strength ◽  
Accessible Porosity ◽  
Rubber Aggregates

Abstract The work presented in this paper aims to study the durability of mortars, in which part of the sand has been replaced with rubber aggregates from used tires and have undergone a surface treatment with a sodium hydroxide solution (NaOH). The substitution rates studied are 10%, 17.5%, and 25%. The results are compared with ordinary mortar and mortars with untreated rubber aggregates while samples with the same substitution rates were used. To do this, the following properties have been studied: compressive strength, flexural tensile strength, water absorption by capillarity, water absorption by total immersion, water-accessible porosity, water permeability, and resistance to the chemical degradation by sulfuric acid H2SO4. The results obtained show that the treatment of rubber aggregates by the solution method (NaOH) presented a considerable improvement in mechanical performance (increase in compressive strength and flexural tensile strength) and better durability compared to reference mortar and mortar with untreated rubber granulate.

scholarly journals Evaluation of the Performance of Bio-Based Rigid Polyurethane Foam with High Amounts of Sunflower Press Cake Particles

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5475
Author(s):  
Agnė Kairytė ◽  
Sylwia Członka ◽  
Renata Boris ◽  
Sigitas Vėjelis
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Polyurethane Foam ◽  
Mechanical Performance ◽  
Positive Impact ◽  
Press Cake ◽  
Rigid Polyurethane Foam ◽  
Average Cell

In the current study, rigid polyurethane foam (PUR) was modified with 10–30 wt.% sunflower press cake (SFP) filler, and its effect on performance characteristics—i.e., rheology, characteristic foaming times, apparent density, thermal conductivity, compressive strength parallel and perpendicular to the foaming directions, tensile strength, and short-term water absorption by partial immersion—was evaluated. Microstructural and statistical analyses were implemented as well. During the study, it was determined that 10–20 wt.% SFP filler showed the greatest positive impact. For instance, the thermal conductivity value improved by 9% and 17%, respectively, while mechanical performance, i.e., compressive strength, increased by 11% and 28% in the perpendicular direction and by 43% and 67% in the parallel direction. Moreover, tensile strength showed 49% and 61% increments, respectively, at 10 wt.% and 20 wt.% SFP filler. Most importantly, SFP filler-modified PUR foams were characterised by two times lower water absorption values and improved microstructures with a reduced average cell size and increased content in closed cells.

Influence of Soil Grading on the Mechanical Behavior of Earth Cement Blocks

MRS Advances ◽  
2020 ◽  
Vol 5 (54-55) ◽  
pp. 2771-2782
Author(s):  
Sathiyapireyanga Jeyasegaram ◽  
Navaratnarajah Sathiparan
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Experimental Program ◽  
Soil Composition ◽  
Fine Content ◽  
Uniformity Coefficient ◽  
Flexural Tensile Strength ◽  
Soil Cement ◽  
Cement Soil

AbstractThe characteristics of earth cement blocks depend on soil composition, grading of the soil, cement-soil ratio and water content, etc… In the present study, an experimental program is conducted to evaluate the influence of soil grading in the mechanical properties of earth cement blocks. Five gradings of soil used for the preparation of earth cement blocks. Soil grading effect on following properties of earth-cement blocks such as block density, compressive strength in wet and dry condition, flexural tensile strength in wet and dry condition, and water absorption was compared. Results show that the properties of the earth cement blocks are dependent upon the fine content and uniformity coefficient of the soil. The increase in the finer content in mortar improves water absorption, compressive strength and flexural tensile strength.

scholarly journals Mechanical and Fracture Parameters of Ultra-High Performance Fiber Reinforcement Concrete Cured via Steam and Water: Optimization of Binder Content

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2016
Author(s):  
Avan Ahmed Mala ◽  
Aryan Far H. Sherwani ◽  
Khaleel H. Younis ◽  
Rabar H. Faraj ◽  
Amir Mosavi
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Performance ◽  
Mechanical Performance ◽  
Binder Content ◽  
Splitting Tensile Strength ◽  
Steam Curing ◽  
Flexural Tensile Strength ◽  
High Performance Fiber ◽  
Curing Methods

An investigational study is conducted to examine the effects of different amounts of binders and curing methods on the mechanical behavior and ductility of Ultra-High Performance Fiber Reinforced Concretes (UHPFRCs) that contain 2% of Micro Steel Fiber (MSF). The aim is to find an optimum binder content for the UHPFRC mixes. The same water-to-binder ratio (w/b) of 0.12 was used for both water curing (WC) and steam curing (SC). Based on the curing methods, two series of eight mixes of UHPFRCs containing different binder contents ranging from 850 to 1200 kg/m3 with an increment of 50 kg/m3 were produced. Mechanical properties such as compressive strength, splitting tensile strength, static elastic module, flexural tensile strength and the ductility behavior were investigated. This study revealed that the mixture of 1150 kg/m3 binder content exhibited the highest values of the experimental results such as a compressive strength greater than 190 MPa, a splitting tensile strength greater than 12.5 MPa, and a modulus of elasticity higher than 45 GPa. The results also show that all of the improvements began to slightly decrease at 1200 kg/m3 of the binder content. On the other hand, it was concluded that SC resulted in higher mechanical performance and ductility behavior than WC.

scholarly journals Preparation, Performance Test, and Microstructure of Composite Modified Reinforced Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shi Hu ◽  
Ying Xu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Water Absorption ◽  
Absorption Rate ◽  
Impact Resistance ◽  
Polypropylene Fiber ◽  
Splitting Tensile Strength ◽  
Aggregate Concrete ◽  
Flexural Tensile Strength

To investigate whether the compound modification means which mixes modified Polyvinyl chloride (PVC) aggregate and polypropylene fiber in concrete could gain “positive hybrid effect” and cope with more sophisticated engineering circumstances, four groups of test specimens were prepared: concrete doped with unmodified PVC aggregate, concrete doped with modified PVC aggregate, concrete doped with unmodified PVC aggregate and polypropylene fiber, and concrete doped with modified PVC aggregate and polypropylene fiber. The fiber content is 0.9 kg/m3, the modified solution content is 1 mol/L NaOH, and the replacement amount of PVC fine aggregate in replacement sand is 0%, 5%, 10%, 20%, and 30%. Mechanical property and durability tests were carried out to compare and analyze the measured compressive strength, splitting tensile strength, flexural tensile strength, water absorption rate, and impact failure energy. Moreover, scanning electron microscopy and XRD diffraction were used to analyze micromorphology and crystal structure of concrete. The test results demonstrate that as the content of PVC aggregate increases, the compressive strength, splitting tensile strength, and flexural tensile strength of the concrete decrease significantly, while the brittleness is improved. Meanwhile, the water absorption rate increases and the impact resistance shows an approximately linear increase trend. Under the same content of PVC aggregate, the most effective way to improve compressive strength is to use modified PVC aggregate. The rapid decrease of compressive strength caused by PVC aggregate can be effectively delayed by doping polypropylene fiber and modified PVC aggregate. Adding polypropylene fiber or using the modified PVC aggregate can improve the brittleness, tensile strength, flexural tensile strength, and impact resistance, but they have different modification and reinforcement effects. The concrete prepared by doping polypropylene fiber and modified PVC aggregate has better performance in tensile strength, flexural tensile strength, brittleness, and impact resistance, and the water absorption and the compressive strength of the concrete are enhanced compared with the normal group. Therefore, composite modified reinforced concrete doped with modified PVC aggregate-polypropylene fiber has broad application prospects.

scholarly journals Mechanical Performance of Concrete Made with Recycled Aggregates from Concrete Pavements

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yancong Zhang ◽  
Lingling Gao ◽  
Wei Bian
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Performance ◽  
Inhibitory Effect ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Concrete Pavements ◽  
Flexural Tensile Strength

This research aims at analysing the mechanical performance of concrete with recycled aggregates from concrete pavements. First, the characteristics of various natural and recycled aggregates used in the concrete were thoroughly analysed. The composition of the recycled aggregates was determined and several physical and chemical tests of the aggregates were performed. In order to evaluate the mechanical performance of recycled concrete, cube compressive strength and flexural tensile strength tests were performed. The effect of recycled aggregates on the strength of recycled concrete is related to the strength of recycled aggregates, the strength of natural aggregates, and the strength of old concrete. The strength of recycled concrete decreases with increasing water-cement ratio. However, due to the water absorption of the recycled aggregate, it has a certain inhibitory effect on the strength reduction. As the replacement rate of recycled aggregates increases, the optimal sand ratio decreases. The sand ratio is controlled between 32% and 38%, which is ideal for recycled concrete. With the increase of fly ash content, the 7 d strength of recycled concrete has decreased to some extent, but the 28 d strength has been slightly improved. In addition, for compressive strength and flexural tensile strength, the optimal content of fly ash is different.

Study of the use of kaolin waste as a partial substitute for fine aggregate in the production of concrete for pavers

2021 ◽  
Vol 2 (2) ◽  
pp. 2474-2489
Author(s):  
Thyago Lima Souza ◽  
Adriano Lopes Gualberto Filho ◽  
Deividy Kaik de Lima Araujo ◽  
Marcos André Lira Silva ◽  
Marco Antônio Assis De Oliveira ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Construction Industry ◽  
Strength Test ◽  
Raw Material ◽  
Fine Aggregate ◽  
Tensile Strength Test ◽  
Flexural Tensile Strength ◽  
Simple Compression

The study of the use of kaolin waste has scientific and socio-environmental value by providing an appropriate destination, reducing the demand and consequent problems arising from its extraction, considering that the construction industry is a consumer of a significant amount of raw material. Thus, the study aims to replace the fine aggregate by kaolin waste in the proportions of 10%, 20% and 30%, verifying its feasibility for interlocking sidewalk pieces. The kaolin waste was used with and without fine material, and physical characterization tests of the materials were performed, and then the concrete pieces were subjected to tests of resistance to simple compression, water absorption and resistance to abrasion, as prescribed by ABNT NBR 9781:2013, and flexural tensile strength test, according to ABNT NBR 12142:2010. According to the results and analyzing the compressive strength at 28 days, the mixtures with replacement of 10% of fine aggregate by kaolin waste reached strengths greater than 35 MPa, an acceptable normative parameter, both for the waste with fines and without fines, making its use feasible.

scholarly journals Influence of the surface treatment of tire rubber residues added in mortars

2008 ◽  
Vol 1 (2) ◽  
pp. 113-120 ◽  
Author(s):  
A. C. Marques ◽  
J. L. Akasaki ◽  
A. P. M. Trigo ◽  
M. L. Marques
Keyword(s):  
Mechanical Properties ◽  
Aqueous Solution ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Surface Treatment ◽  
Water Absorption ◽  
Modulus Of Elasticity ◽  
Tire Rubber ◽  
Flow Test ◽  
Made In

In this work it was evaluated the influence tire rubber addition in mortars in order to replace part of the sand (12% by volume). It was also intended to verify if the tire rubber treatment with NaOH saturated aqueous solution causes interference on the mechanical properties of the mixture. Compressive strength, splitting tensile strength, water absorption, modulus of elasticity, and flow test were made in specimens of 5cmx10cm and the tests were carried out to 7, 28, 56, 90, and 180 days. The results show reduction on mechanical properties values after addition of tire rubber and decrease of the workability. It was also observed that the tire rubber treatment does not cause any alteration on the results compared to the rubber without treatment.

scholarly journals Effect of Curing Method on Properties of Lightweight Foamed Concrete

2018 ◽  
Vol 7 (2.29) ◽  
pp. 927 ◽  
Author(s):  
Bishir Kado ◽  
Shahrin Mohammad ◽  
Yeong Huei Lee ◽  
Poi Ngian Shek ◽  
Mariyana Aida Ab Kadir
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Precast Concrete ◽  
Construction Materials ◽  
Splitting Tensile Strength ◽  
Structural Members ◽  
Lightweight Construction ◽  
Foamed Concrete ◽  
Curing Method

Lightweight construction is aimed to achieve a sustainable feature by reducing transportation frequency and construction materials usage during construction phase. Lightweight precast concrete may serve an alternative for the lightweight construction. There are rarely application can be found for structural members as lightweight panels always to be used for secondary or non-load bearing members. This paper presents an experimental study on properties (compressive strength, splitting tensile strength, water absorption) of lightweight foamed concrete (LFC) at two different curing methods. LFC with densities of 1500, 1700, and 1800 kg/m3, cement-sand ratio of 2:1 and water-cement ratio of 0.5 were investigated. The results showed LFC can be produced with the properties ofdensity range of 1500 to 1800 kg/m3 and corresponding compressive strength of 10 to 39 MPa. The higher the density of LFC, the less the water absorption for all the curing method considered, the highest and the lowest water absorption was 11.3% and 2.0% for 1500 kg/m3 cured in water and 1800 kg/m3 cured in air respectively. Compressive strength of LFC increases with age and density while water cured LFC has high compressive strength. Splitting tensile strength increases with density of LFC, but air cured LFC has more splitting tensile strength than water cured of the same density. The highest splitting tensile strength recorded was 3.92 MPa for 1800 kg/m3 cured in air, which was about 16% of its compressive strength at 28 days of curing age. These properties are important and can be applied to LFC precast structural members with air or water curing method which have less references for LFC in structural usage.  

scholarly journals Partial Replacement of Cement with Waste Paper Sludge Ash

2021 ◽  
Vol 9 (11) ◽  
pp. 1975-1983
Author(s):  
Shahid Bashir
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Cement Industry ◽  
Waste Paper ◽  
Partial Replacement ◽  
Dry Density ◽  
Paper Sludge ◽  
Paper Sludge Ash ◽  
Sludge Ash

Abstract: Cement production is one of the sources that emit carbon dioxide, in addition to deforestation and combustion of fossil fuels also leads to ill effects on environment. The global cement industry accounts for 7% of earth’s greenhouse gas emission. To enhance the environmental effects associated with cement manufacturing and to constantly deplore natural resources, we need to develop other binders to make the concrete industry sustainable. This work offers the option to use waste paper sludge ash as a partial replacement of cement for new concrete. In this study cement in partially replaced as 5%, 10%, 15% and 20% by waste paper sludge ash in concrete for M25 mix and tested for compressive strength, tensile strength, water absorption and dry density up to the age of 28days and compared it with conventional concrete, based on the results obtained, it is found that waste paper ash may be used as a cement replacement up to 5% by weight and the particle size is less the 90µm to prevent reduction in workability. Keywords: slump test, Compressive strength, split tensile strength, water absorption test, Waste Paper Sludge Ash Concrete, Workability.

scholarly journals The Effect of Nano Metakaolin Material on Some Properties of Concrete

2013 ◽  
Vol 6 (1) ◽  
pp. 50-61
Author(s):  
Amer M. Ibrahem ◽  
Shakir A. Al-Mishhadani ◽  
Zeinab H.Naji
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Thermal Activation ◽  
Ordinary Portland Cement ◽  
Splitting Tensile Strength ◽  
Kaolin Clay ◽  
Cement Ratio ◽  
Water Cement Ratio

This investigation aimed to study the effect of nano metakaolin ( NMK ) on some properties (compressive strength ,splitting tensile strength & water absorption ) of concrete. The nano metakaolin (NMK) was prepared by thermal activation of kaolin clay for 2 hours at 750 Ċ. The cement used in this investigation consists of ordinary Portland cement (OPC). The OPC was partially substituted by NMK of ( 3, 5 & 10%) by weight of cement. The C45 concrete was prepared , using water/cement ratio ( W/c) of (0.53) .The Water absorption was tested at 28 days while the tests (compressive strength ,splitting tensile strength) were tested at ages of (7, 28, 60,& 90) days . The compressive strength and splitting tensile strength of concrete with NMK were higher than that of reference concrete with the same W/c ratio.The improvement in the compressive strength when using NMK was (42.2, 55.8 , 63.1% ) at age 28 days for ( 3%, 5%, &10% ) replacement of NMK respectively whereas the improvement in the splitting tensile strength was (0% , 36% & 46.8 %) at age of 28 days when using (3%, 5%, &10% ) NMK respectively. The improvement in the water absorption was (16.6%, 21.79%, &25.6 ) when using (3, 5, &10% )NMK.

Sign in / Sign up

Export Citation Format

Share Document