EFFECT OF NANO-SILICA, SILICA FUME, CEMENT CONTENT AND CURING CONDITIONS ON THE CONCRETE COMPRESSIVE STRENGTH AT 7 AND 28 DAYS

This research aims to study the influences of three types of Nano materials on concrete compressive strength, considered Nano types were Nano-Iron Oxide Fe2O3 (NF), Nano-Manganese Oxide Mn2O3 (NM), and Nano-Silica SiO2 (NS). A constant concrete mix and water content were considered. The used percentages of different types of (NF, NM, and NS) that replaced by the cement content were (0.5, 1.0, 2.0, and 5.0%) of mixture weight (wt). The results demonstrated that the (NS) Nano type has better effect than other types on the concrete compressive strength.

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THE SUITABILITY OF SEAWATER ON CONCRETING IN THE NIGER – DELTA ZONE

UMUDIKE JOURNAL OF ENGINEERING AND TECHNOLOGY ◽

10.33922/j.ujet_v5i1_6 ◽

2019 ◽

pp. 39-48

Keyword(s):

Compressive Strength ◽

Niger Delta ◽

Mathematical Theory ◽

Regression Models ◽

Cement Content ◽

Suitable Condition ◽

Maximum Level ◽

Minimum Level ◽

Concrete Compressive Strength ◽

Factorial Regression

This study was carried out in order to determine the suitability or otherwise of seawater for concreting. The study was carried out using the Box-Wilson symmetric composite plan B3, comprising 15 experimental points with 3 levels of treatment each. In accordance with the principle of the mathematical theory of experiment, multi-factorial regression models were evolved. The cement content at maximum level[x1 (+), water content at the minimum level [x2 (-)] and retarding admixture at minimum level of treatment [x3(-)] proved to be the most suitable condition for concreting. The result as follows were; Concrete slump: 60mm, Concrete density: 2450g/cm3, Concrete compressive strength: 22.56N/mm2, 26.65N/mm2 and 30.09N/mm2 for 7days, 14days and 28 days, respectively.

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EFFECTS OF REPLACING CEMENT BY DATE PALM TREES WASTES ON CONCRETE PERFORMANCE

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.2021.8(1).mat-13 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Ahmad Salah Edeen Nassef ◽

Kalifa Hamed AlMuqbali ◽

Sheikha Mahmood Al Naqabi

Keyword(s):

Compressive Strength ◽

Date Palm ◽

Cement Content ◽

Concrete Strength ◽

Palm Tree ◽

Compression Tests ◽

Tree Leaves ◽

Concrete Compressive Strength ◽

Sustainable Environment ◽

Palm Trees

This paper was studying the effects of palm tree wastes on the behavior of the concrete to reduce cement content in the concrete to ensure a sustainable environment. Both fibers of palm tree and the ash of palm tree leaves are used in this study considering different percentages of palm tree wastes, which are replaced the cement, to investigate both of workability and strength of the concrete. Also, the combination of palm tree leaves ash and fibers of palm trees is investigated. The slump and compression tests are carried out to evaluate both workability and concrete strength. The palm fibers were reducing the workability of concrete at both of different percentage of replacement and different fiber lengths. The slump is reduced by 26.667% at 2 cm fibers length and it is completely lost at 5 cm length fibers at the same percentage of replacement of 5% of the cement content. The palm fibers were weakening concrete compressive strength at different percentages and different fiber lengths. Palm leaves ash was enhancing concrete workability and concrete compressive strength.

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Effect of coarse aggregate size on strength and workability of concrete

Canadian Journal of Civil Engineering ◽

10.1139/l05-090 ◽

2006 ◽

Vol 33 (2) ◽

pp. 206-213 ◽

Cited By ~ 12

Author(s):

Peter J Tumidajski ◽

B Gong

Keyword(s):

Compressive Strength ◽

Water Demand ◽

Coarse Aggregate ◽

Cement Content ◽

Aggregate Size ◽

Concrete Compressive Strength ◽

Aggregate Fraction ◽

Maximum Compressive Strength

The properties of concrete were studied when the proportions of 37.5 and 19.5 mm stone in the coarse aggregate were varied. With the cement content of 160 kg/m3 and the ratio of water/cement (w/c) greater than 0.9, the compressive strength is maximum at 25 percent by weight (w/o) of 37.5 mm stone. Conversely, for the cement content of 350 kg/m3 and w/c ratios of less than 0.50, maximum compressive strength is substantively reduced. For both 160 kg/m3 and 350 kg/m3 cement contents, workability improves slightly as the proportion of the 37.5 mm stone is increased. For 100 mm fixed slumps and cement content of less than 160 kg/m3, there was little change in compressive strength as the proportion of 37.5 mm stone increased. However, when cement content was increased from 190 to 350 kg/m3, maximum compressive strength was observed, which shifted downward from 50 w/o to 25 w/o of 37.5 mm stone. In general, to maintain a 100 mm slump, water demand decreased as the proportion of 37.5 mm stone in the coarse aggregate fraction increased.Key words: concrete, compressive strength, workability, slump, aggregate, size, cement.

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Test on axial compression performance of nano-silica concrete-filled angle steel reinforced GFRP tubular column

Nanotechnology Reviews ◽

10.1515/ntrev-2019-0047 ◽

2019 ◽

Vol 8 (1) ◽

pp. 523-538 ◽

Cited By ~ 10

Author(s):

Kang He ◽

Yu Chen ◽

Wentao Xie

Keyword(s):

Compressive Strength ◽

Bearing Capacity ◽

Thickness Ratio ◽

Nano Silica ◽

Concrete Compressive Strength ◽

Initial Stiffness ◽

Load Bearing Capacity ◽

Load Bearing ◽

Angle Section ◽

Angle Steel

AbstractThis paper attempts to investigate the effect of various parameters on the axial compressive behavior of nano-silica concrete-filled angle steel reinforced GFRP tubular columns. The proposed new composite column consists of three parts: the outer GFRP tube, the inner angle section steel and the nano-silica concrete filled between GFRP tube and angle section steel. Twenty-seven specimens with different nano-silica concrete compressive strength (20MPa, 30MPa and 40MPa), diameter-to-thickness ratio of GFRP tube (20, 25 and 40) and steel ratio (0.008, 0.022 and 0.034) were tested under axial load. The main purpose of this study is to examine the effect of the three parameters on the following: failure modes, deformation capacity, load bearing capacity, ductility and initial stiffness of the new composite column under axial load. It was found that the load bearing capacity and initial stiffness increased as the nano-silica concrete compressive strength of the specimens increased. But the specimens with higher nano-silica concrete compressive strength showed lower deformation capacity than that of the specimens with lower nano-silica concrete compressive strength. The varieties of the steel ratio have no significant effect on the specimens’ axial deformation behavior. Experimental results also showed that both load bearing capacity and deformation capacity increased with the decrease of diameter-to-thickness ratio of GFRP tube. However, diameter-to-thickness ratio of GFRP tube has no significant effect on the initial stiffness of specimens. The confinement coefficient was proposed to better evaluate the confinement effect of GFRP tube on the inner angle section steel reinforced core nano-silica concrete. The confinement effect of GFRP tube on lower strength concrete was better, and the confinement effect reduced as the diameter-to-thickness ratio of GFRP tube increased. The design formulas for the load bearing capacity of the nano-silica concrete-filled angle steel reinforced GFRP tubular columns under axial load were proposed.

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Laboratory Experimental Research on Mix Ratio Test of Cement Soil

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.438-439.197 ◽

2013 ◽

Vol 438-439 ◽

pp. 197-201

Author(s):

Xian Hua Yao ◽

Peng Li ◽

Jun Feng Guan

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Unconfined Compressive Strength ◽

Cement Content ◽

Ratio Test ◽

Curing Time ◽

Curing Conditions ◽

Cement Ratio ◽

Water Cement Ratio ◽

Cement Soil

Based on the generalization and analysis of laboratory experimental results on mix ratio, the effects of various factors such as cement content, water-cement ratio, curing time, curing conditions and types of cement on the mechanical properties of unconfined compressive strength of cement soil are presented. Results show that the unconfined compressive strength of cement soil increases with the growing curing time, and it is greatly affected by the cement content, water-cement ratio, cement types and curing time, while the effect of curing conditions is weak with a cement content of more than 10%. Moreover, the stress-strain of the cement soil responds with the cement content and curing time, increasing curing time and cement content makes the cement soil to be harder and brittle, and leads to a larger Young's modulus.

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The effect of Vietnam’s nano-silica on mechanical properties of high-performance concrete

Transport and Communication Science Journal ◽

10.47869/tcsj.72.1.9 ◽

2021 ◽

Vol 72 (1) ◽

pp. 76-83

Author(s):

Lam Le Hong ◽

Lam Dao Duy ◽

Huu Pham Duy

Keyword(s):

Compressive Strength ◽

Silica Fume ◽

High Performance ◽

High Performance Concrete ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Nano Silica ◽

Nano Sio2 ◽

Curing Period ◽

Compressive Strength Test

The demand for High Performance Concrete (HPC) is steadily increasing with massive developments. Conventionally, it is possible to use industrial products such as silica fume (SF), fly ash, as supplementary cementitious materials (SCM), to enhance the attributes of HPC. In recent years, nano-silica (NS) is used as an additive in added mainly to fill up the deviation arises with the addition of SF for HPC. This study aims to optimize the proportion of NS (produced in Vietnam) in the mixture used for fabricating 70 MPa high-performance concrete. SiO2 powder with particle size from 10 to 15 nm were used for mixing. A series of compressive strength test of HPC with nano-SiO2 varied from 0 to 2.8 percent of total of all binders (0%, 1.2%, 2%, 2.8%), and the fixed percentage of silica fume at 8% were proposed. Results show compressive strength increases with the increase of nano-SiO2, but this increase stops after reaching 2%. And at day 28 of the curing period, only concrete mixture containing of 8% silica fume and 2% nano-SiO2, had the highest compressive strength.

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Effect of Curing Condition on Some Properties of Cement Stabilized Lateritic Interlocking Bricks

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.824.37 ◽

2013 ◽

Vol 824 ◽

pp. 37-43 ◽

Cited By ~ 2

Author(s):

Manasseh Joel ◽

Joseph E. Edeh

Keyword(s):

Compressive Strength ◽

Water Absorption ◽

Conventional Method ◽

Cement Content ◽

Soil Classification ◽

Curing Conditions ◽

Curing Condition ◽

Condition C

The effect of three different curing conditions on the compressive strength and water absorption of lateritic interlocking bricks, produced with laterite stabilized with 0 %, 2 %, 4 %, 6 % and 8 % cement content was investigated. The study is aimed at providing an alternative to the conventional method of curing interlocking bricks. The three curing conditions used in the study are A (covering of bricks with tarpaulin after sprinkling with water twice a day) B (complete immersion in water) C (complete covering with air and water tight polythene bags). Laterite used in the production of interlocking bricks was as an A-2-7 soil, using the AASHTO system of soil classification. Compressive strength of bricks increased with cement content and days under the different curing conditions, 28 day optimum compressive strength values of 4.28 N/mm2, 3.67 N/mm2 and 3.67 N/mm2 at 8 % cement content was obtained from bricks using curing condition C B and A respectively. Water absorption value decreased with cement content under the different curing conditions, minimum water absorption values of 2.44 %, 1.68 % and 1.72 % at 8 % cement content was obtained with bricks cured under curing condition A B and C respectively. Based on results of test, curing condition C is recommended for use in the production of cement stabilized interlocking bricks, as this will enhance effective production of interlocking bricks in areas where water is scarce.

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Analysis of Post-Combustion High-Strength Concrete Compressive Strength Using Polypropylene Fibers

MEDIA KOMUNIKASI TEKNIK SIPIL ◽

10.14710/mkts.v26i1.28262 ◽

2020 ◽

Vol 26 (1) ◽

pp. 118-127

Author(s):

Teuku Budi Aulia ◽

Muttaqin Muttaqin ◽

Mochammad Afifuddin ◽

Zahra Amalia

Keyword(s):

Compressive Strength ◽

Thermal Stress ◽

Silica Fume ◽

High Temperatures ◽

High Strength Concrete ◽

High Strength ◽

Polypropylene Fibers ◽

Concrete Compressive Strength ◽

Strength Concrete ◽

Maximum Value

High-strength concrete is vulnerable to high temperatures due to its high density. The use of polypropylene fibers could prevent structure explosion by forming canals due to melted fibers during fire, thus release its thermal stress. This study aims to determine the effect of polypropylene fibers on compressive strength of high-strength concrete after combustion at 400ºC for five hours. High-strength concrete was made by w/c-ratio 0.3 with cement amount 550 kg/m3 and added with silica fume 8% and superplasticizer 4% by cement weight. The variations of polypropylene fibers were 0%, 0.2% and 0.4% of concrete volume. The compression test was carried out on standard cylinders Ø15/30 cm of combustion and without combustion specimens at 7 and 28 days. The results showed that compressive strength of high-strength concretes without using polypropylene fibers decreased in post-combustion compared with specimens without combustion, i.e., 0.81% at 7 days and 23.42% at 28 days. Conversely, the use of polypropylene fibers can increase post-combustion compressive strength with a maximum value resulted in adding 0.2% which are 25.52% and 10.44% at 7 and 28 days respectively. It can be concluded that the use of polypropylene fibers is effective to prevent reduction of high-strength concrete compressive strength that are burned at high temperatures.

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