Influence of the concrete mixture compaction time on density and compressive strength of hardened concrete samples

Different particle sizes of waste rubber are mixed according to natural fine aggregate gradation to replace the fine aggregate in concrete by weight. And the effect of waste rubber content on performances of concrete mixture, the mechanics, frost resisting, thermal insulation of hardened concrete are studied. The results show that the slump and apparent density of concrete mixture decreases with the increase of waste rubber content. Compressive strength of the hardened concrete also decreases obviously with the increase of waste rubber content and compressive strength decreases by 46.5% when the content is 30%; compared with ordinary concrete, the freeze-thaw resistance of concrete with waste rubber powder is obviously improved; thermal conductivity of concrete with waste rubber is only 13% of ordinary concrete, and the concrete with less than 20% wt. of waste rubber has low water absorption and good water resistance.

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Influence of Anti-Slip Aggregate on Properties of Hardened Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.870.39 ◽

2020 ◽

Vol 870 ◽

pp. 39-47

Author(s):

Waseem Hamzah Mahdi ◽

Layth Abdul Rasool Mahdi ◽

Ruba H. Kadhim ◽

Gufraan A. Kadhim

Keyword(s):

Compressive Strength ◽

Flexural Strength ◽

Strength Properties ◽

Concrete Mixture ◽

Hardened Concrete ◽

New Materials ◽

Natural Sand ◽

Concrete Properties ◽

Normal Strength ◽

Tensile Splitting Strength

Nowadays, applying new materials is widely used in concrete construction to study their effects in enhancing the properties and the durability of concrete. This research includes studying the using of manufactured aggregate, which is so-called '' Anti-slip sand '' in specific proportions to know its influence on strength properties of normal strength hardened concrete which involves compressive strength, flexural strength, tensile splitting strength, and density. Anti-slip sand at different rates of (25%, 50%, 75%, and 100%) replaces the natural sand in the concrete mixture to investigate its effect on the properties of concrete. The study shows that the best results of concrete properties are found when replaced the natural sand by 100% of anti-slip sand. Compressive, flexural and tensile strengths of concrete are increased with increment ratios of (44%, 40%, and 20%) respectively compared with other concrete mixture contains only natural sand. In addition, the study shows that the density of hardened concrete is decreased from 2420 kg/m3 in concrete with 100% natural sand to 2360 kg/m3 with a decrement ratio of 2.5% in concrete with 100% anti-slip sand.

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Effect of Calcium Nitrate on the Properties of Portland–Limestone Cement-Based Concrete Cured at Low Temperature

Materials ◽

10.3390/ma14071611 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1611

Author(s):

Gintautas Skripkiūnas ◽

Asta Kičaitė ◽

Harald Justnes ◽

Ina Pundienė

Keyword(s):

Compressive Strength ◽

Cement Paste ◽

Setting Time ◽

Calcium Nitrate ◽

Curing Temperature ◽

Hardened Concrete ◽

Cement Pastes ◽

Initial Setting Time ◽

Initial Setting ◽

Early Strength

The effect of calcium nitrate (CN) dosages from 0 to 3% (of cement mass) on the properties of fresh cement paste rheology and hardening processes and on the strength of hardened concrete with two types of limestone-blended composite cements (CEM II A-LL 42.5 R and 42.5 N) at different initial (two-day) curing temperatures (−10 °C to +20 °C) is presented. The rheology results showed that a CN dosage up to 1.5% works as a plasticizing admixture, while higher amounts demonstrate the effect of increasing viscosity. At higher CN content, the viscosity growth in normal early strength (N type) cement pastes is much slower than in high early strength (R type) cement pastes. For both cement-type pastes, shortening the initial and final setting times is more effective when using 3% at +5 °C and 0 °C. At these temperatures, the use of 3% CN reduces the initial setting time for high early strength paste by 7.4 and 5.4 times and for normal early strength cement paste by 3.5 and 3.4 times when compared to a CN-free cement paste. The most efficient use of CN is achieved at −5 °C for compressive strength enlargement; a 1% CN dosage ensures the compressive strength of samples at a −5 °C initial curing temperature, with high early strength cement exceeding 3.5 MPa but being less than the required 3.5 MPa in samples with normal early strength cement.

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Effects of Loading Percentage of Polyurethane in Lightweight Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.357-360.1082 ◽

2013 ◽

Vol 357-360 ◽

pp. 1082-1085 ◽

Cited By ~ 1

Author(s):

Kamarul Aini Mohd Sari ◽

Sohif Mat ◽

Khairiah Haji Badri ◽

Muhammad Fauzi Mohd Zain

Keyword(s):

Thermal Conductivity ◽

Compressive Strength ◽

Lightweight Concrete ◽

Palm Kernel ◽

Physical And Mechanical Properties ◽

Concrete Mixture ◽

Experimental Program ◽

Polymer Concrete ◽

Optimum Level ◽

Methylene Diphenyl Diisocyanate

An experimental program was performed to obtain the density, compressive strength, and thermal conductivity of palm-based lightweight concrete. Palm-based polyurethane (PU) particles were used as lightweight aggregates in creating concrete systems. Concrete systems contain palm kernel oil-based polyol (PKO-p) reacted with 2,4-methylene diphenyl diisocyanate (MDI). In this study, polymer concrete was improved to achieve the optimum level of PU with the lowest possible density. The PU particles in the concrete mixture comprised of 1% to 5% w/w with density of less than 1800 kg/m3. The PU particles were 5 mm in size. The ratio of PKO-p to MDI was set at 1:1 and the loading of the concrete mixture was set at 3% w/w to produce lightweight concrete. The resulting concrete has excellent compressive strength (17.5 MPa) and thermal conductivity (0.24 W/mK). Results show that the PU particle dosage has the most significant effect on the physical and mechanical properties of concrete.

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A sustainable approach to optimum utilization of used foundry sand in concrete

Science and Engineering of Composite Materials ◽

10.1515/secm-2017-0012 ◽

2018 ◽

Vol 25 (5) ◽

pp. 927-937 ◽

Cited By ~ 1

Author(s):

Khuram Rashid ◽

Sana Nazir

Keyword(s):

Compressive Strength ◽

Modulus Of Elasticity ◽

Research Work ◽

Hardened Concrete ◽

Prediction Formula ◽

Foundry Sand ◽

Foundry Sands ◽

Fine Aggregates ◽

Optimum Utilization ◽

Conservation Of Natural Resources

AbstractConservation of natural resources, healthy environments, and optimal utilization of waste materials are intimate needs of the present time, and this research work was carried out to fulfill these needs. In this experimental and analytical study, concrete was prepared by replacing natural fine aggregates with two types of used foundry sands by 10%, 20% and 30% (by volume). The properties of fresh and hardened concrete were investigated and compared with a replacement amount of fine aggregates from 0% to 30%. Compressive strength was evaluated after 7, 28 and 63 days of moist curing. Along with compressive strength, the modulus of elasticity was also investigated and a reduction in compressive strength and modulus of elasticity was observed with the increase in the amount of used foundry sand. A prediction formula was proposed to predict the compressive strength, and verified by current experimental observations and also with a large database that was also established in this work. The prediction formula may be considered as very helpful for predicting the potential of using used foundry sand as an aggregate in concrete.

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Effect of Water Cement Ratios on Compressive Strength of Palm Kernel Shell Concrete

LAUTECH Journal of Civil and Environmental Studies ◽

10.36108/laujoces/9102/20(0121) ◽

2019 ◽

Vol 2 (Issue 1) ◽

Author(s):

A.O Adeyemi ◽

M.A Anifowose ◽

I.O Amototo ◽

S.A Adebara ◽

M.Y Olawuyi

Keyword(s):

Compressive Strength ◽

Coarse Aggregate ◽

Fresh Concrete ◽

Palm Kernel ◽

Hardened Concrete ◽

Cement Ratio ◽

Water Cement Ratio ◽

Palm Kernel Shell ◽

Compressive Strength Of Concrete ◽

Palm Kernel Shells

This study examined the effect of varying water cement ratio on the compressive strength of concrete produced using palm kernel shell (PKS) as coarse aggregate at different replacement levels. The replacement levels of coarse aggregate with palm kernel shells (PKS) were 0%, 25%, 50%, and 100% respectively. PKS concrete cubes (144 specimens) of sizes 150mm x 150mm x 150mm were cast and cured in water for 7, 14, 21 and 28 days respectively. A mix ratio of 1:2:4 was adopted with water-cement ratio of 0.45, 0.5, and 0.6 respectively while the batching was done by weight. Slump test was conducted on fresh concrete while compressive strength test was carried out on the hardened concrete cubes using a compression testing machine of 2000kN capacity. The result of tests on fresh concrete shows that the slump height of 0.45 water cement ratio (w/c) increases with an increase in PKS%. This trend was similar to 0.50 and 0.60 w/c. However, the compressive strength of concrete cube decreases with an increase in w/c (from 0.45 to 0.60) but increases with respect to curing age and also decreases with increase in PKS%. Concrete with 0.45 water-cement ratio possess the highest compressive strength. It was observed that PKS is not a good substitute for coarse aggregate in mix ratio 1:2:4 for concrete productions. Hence, the study suggest the use of chemical admixture such as superplasticizer or calcium chloride in order to improve the strength of palm kernel shells-concrete.

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Pengaruh Penambahan Sat Additive Addition H.E Terhadap Kuat Tekan Beton

Jurnal Ilmiah Vastuwidya ◽

10.47532/jiv.v2i1.74 ◽

2020 ◽

Vol 2 (1) ◽

pp. 31-57

Author(s):

Ni Ketut Sri Astati Sukawati

Keyword(s):

Compressive Strength ◽

Concrete Mixture ◽

Partial Replacement ◽

Work Related ◽

Coarse Aggregates ◽

Alternative Ingredients ◽

Fine Aggregates ◽

Compressive Strength Test ◽

Compressive Strength Of Concrete ◽

Artificial Stone

Concrete with various variants is a basic requirement in building a building. The concrete mixture is diverse depending on the planning made beforehand. The cement mixture is usually in the form of a mixture of artificial stone, cement, water and fine aggregates and coarse aggregates. Aggregates (fine aggregates and coarse aggregates) function as fillers in concrete mixtures. (Subakti, A., 1994). However, in building construction, additives are often added, but there is still a sense of uncertainty at the time of dismantling the mold and the reference before the concrete reaches sufficient strength to carry its own weight and the carrying loads acting on it. To overcome the time of carrying out work related to concrete, it is necessary to find an alternative solution, for example by looking for alternative ingredients of concrete mixture on the basis of consideration without reducing the quality of the concrete. From the results of previous studies it was stated that due to the partial replacement of cement with Fly Ash, the strength of the pressure and tensile strength of the concrete had increased (Budhi Saputro, A., 2008). Based on the description above, the author seeks to examine how the compressive strength of concrete characteristics that occur by adding additives Addition H.E in the concrete mixture and is there any additive Additon H.E effect on the increase in the compressive strength characteristic of the concrete. From the results of the study, it was found that the compressive strength of the concrete with the addition of additives HE was that after the compressive strength test of the concrete cube was carried out and the analysis of concrete compressive strength of 10 specimens, in each experiment a cube specimen was made with the addition of additons. HE with a dose of 80 cc, 120 cc, and 200 cc can accelerate and increase the compressive strength of concrete characteristics.

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Pengaruh Pemanfaatan Abu Tumbuhan Perumpung Terhadap Peningkatan Kuat Tekan Beton K300

Jurnal Tekno ◽

10.33557/jtekno.v18i2.1386 ◽

2021 ◽

Vol 18 (2) ◽

pp. 11-20

Author(s):

Ahmad Junaidi ◽

R Dewo Hiraliyamaesa Hariyanto

Keyword(s):

Compressive Strength ◽

Test Object ◽

Concrete Mixture ◽

Wild Plant ◽

Concrete Compressive Strength ◽

Normal Concrete ◽

Compressive Strength Of Concrete ◽

Test Objects

Perumpung (Eulalia japonica) is a wild plant that usually grows on the banks of river. The locals consider this plant as a waste/pest, but the authors are interested in researching perumpung because they are similar to bamboo, sugarcane and other fibrous plants. In this study, the authors aims to compare the compressive strength of normal concrete with the compressive strength of concrete added with Perumpung ash at 28-days-old K-300. The study used a cube-shaped test object (15 x 15 x 15 cm) with 6 samples for each condition. The total number of test objects is 48, which consists of 8 conditions, namely normal conditions and 5%, 7.5%, 10%, 12.5%, 15%, 17.5% and 20% addition of perumpung ash by cement weight. The results obtained that the compressive strength of 28-days-old concrete under normal conditions was 316,060 kg/cm2 and the addition of 5% ash was 331.583 kg/cm2, 7.5% was 337.181 kg/cm2, 10% was 341.813 kg/cm2, 12 ,5% is 347,045 kg/cm2, 15% is 353,889 kg/cm2, 17.5% is 311,160 kg/cm2 and 20% is 298.44 kg/cm2. From the results above it can be concluded that the addition of 15% Perumpung Ash to the concrete mixture increases the maximum characteristic concrete compressive strength by 353.889 kg/cm2.

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PENGARUH PENGGUNAAN LIMBAH PLASTIK POLYPROPYLENE (PP) SEBAGAI CAMPURAN AGREGAT KASAR TERHADAP KUAT TEKAN DAN TARIK PADA BETON FC’ 25 MPA

Jurnal Infrastruktur ◽

10.35814/infrastruktur.v3i2.706 ◽

2019 ◽

Vol 3 (2) ◽

pp. 81-89

Author(s):

Angga Pirman Firdaus ◽

Jonbi

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Strength Test ◽

Plastic Waste ◽

Concrete Mixture ◽

Strength Testing ◽

Concrete Compressive Strength ◽

Tensile Strength Test ◽

Compressive Strength Test ◽

Waste Mixture

Indonesia ranks second in the world's largest plastic waste producer after China. Each year, Indonesia can contributeup to 187.2 million tons of plastic waste, while China reaches 262.9 million tons of plastic waste. Based on the data, one way to utilize plastic waste by using plastic waste as a mixture of concrete, where the plastic used is polypropylene (PP) plastic with different percentage of concrete mixture, the test includes compressive strength test and tensile concrete. The results of concrete compressive strength testing with polypropylene (PP) plastic waste mixture of 5%, 10% and 15% at age 28 in aggregate aggregate mixture decreased by 5.15%, 6.89% and 13.53%. As for the result of concrete tensile strength test with polypropylene (PP) plastic waste mixture of 5%, 10% and 15% at age 28 in crude aggregate mixture decreased 17,61%, 24,13% dan 23,24%.

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Utilization of Sugarcane Bagasse Ash from Power Co-generation Boilers as a Supplementary Cementitious Material

East African Journal of Science, Technology and Innovation ◽

10.37425/eajsti.v2i2.175 ◽

2021 ◽

Vol 2 (2) ◽

Author(s):

Safiki Ainomugisha ◽

Bisaso Edwin ◽

Bazairwe Annet

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Sugarcane Bagasse ◽

Low Income ◽

Ordinary Portland Cement ◽

Construction Material ◽

Sustainable Construction ◽

Partial Replacement ◽

Hardened Concrete ◽

Sugarcane Bagasse Ash

Concrete has been the world’s most consumed construction material, with over 10 billion tons of concrete annually. This is mainly due to its excellent mechanical and durability properties plus high mouldability. However, one of its major constituents; Ordinary Portland Cement is reported to be expensive and unaffordable by most low-income earners. Its production contributes about 5%–8% of global CO2 greenhouse emissions. This is most likely to increase exponentially with the demand of Ordinary Portland Cement estimated to rise by 200%, reaching 6000 million tons/year by 2050. Therefore, different countries are aiming at finding alternative sustainable construction materials that are more affordable and offer greener options reducing reliance on non-renewable sources. Therefore, this study aimed at assessing the possibility of utilizing sugarcane bagasse ash from co-generation in sugar factories as supplementary material in concrete. Physical and chemical properties of this sugarcane bagasse ash were obtained plus physical and mechanical properties of fresh and hardened concrete made with partial replacement of Ordinary Portland Cement. Cost-benefit analysis of concrete was also assessed. The study was carried using 63 concrete cubes of size 150cm3 with water absorption studied as per BS 1881-122; slump test to BS 1881-102; and compressive strength and density of concrete according to BS 1881-116. The cement binder was replaced with sugarcane bagasse ash 0%, 5%, 10%, 15%, 20%, 25% and 30% by proportion of weight. Results showed the bulk density of sugarcane bagasse ash at 474.33kg/m3, the specific gravity of 1.81, and 65% of bagasse ash has a particle size of less than 0.28mm. Chemically, sugarcane bagasse ash contained SiO2, Fe2O3, and Al2O3 at 63.59%, 3.39%, and 5.66% respectively. A 10% replacement of cement gave optimum compressive strength of 26.17MPa. This 10% replacement demonstrated a cost saving of 5.65% compared with conventional concrete.

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