scholarly journals A study on the influence of curing on the strength of a standard grade concrete mix

2010 ◽  
Vol 8 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Rao Krishna ◽  
Rathish Kumar ◽  
Azhar Khan
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Ordinary Portland Cement ◽  
Test Results ◽  
Accelerated Curing ◽  
Design Life ◽  
Curing Method ◽  
The One ◽  
Curing Compound ◽  
Portland Pozzolana Cement

Curing is essential if concrete is to perform the intended function over the design life of the structure while excessive curing time may lead to the escalation of the construction cost of the project and unnecessary delays. Where there is a scarcity of water and on sloping surfaces where curing with water is difficult and in cases where large areas like pavements have to be cured, the use of curing compound may be resorted to. The parameters of the study include the curing period [1, 3, 7, 14 and 28 day], curing method [conventional wet curing, membrane forming compound curing and accelerated curing] and the type of cement [Ordinary Portland Cement(OPC) 43 grade, Portland Pozzolana Cement(PPC) 43 grade and Ordinary Portland Cement(OPC) 43 grade +10% Silica Fume(SF) replacement for cement]. In all a total of 99 cube specimens were cast and cured under different conditions before testing. Test results indicate a drop in strength at all ages for concretes with PPC and the one in which 10% OPC is replaced by silica Fume(SF) in comparison with the concrete with OPC. Curing by membrane forming curing compound yielded nearly the same results as that of conventional wet curing for concrete with OPC and there was a marginal decrement in concrete with PPC. Predicted 28-day strength of concrete from the accelerated curing test was found to be on a conservative side compared to control concrete.

PENGARUH JENIS SEMEN DAN PENAMBAHAN SILICA FUME TERHADAP KEKUATAN DAN DURABILITAS BETON

2012 ◽  
Vol 2 (1) ◽  
pp. 25
Author(s):  
Ariyadi Basuki ◽  
Maulana Ikhwan Sadikin
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Ordinary Portland Cement ◽  
Composite Cement

Dalam penelitian ini dilakukan serangkaian pengujian untuk mengetahui sifat fisik dari material penyusun (agregat), yang kemudian dirancang komposisi rencana beton dengan mutu K250 (normal/kontrol) dan K250 dengan aditif Silica Fume 10% dari berat semen. Variasi campuran menggunakan tiga tipe semen yang berbeda yaitu Ordinary Portland Cement (OPC)/ Semen Tipe I, Portland Composite Cement (PCC) dan Semen Tipe II. Proses dilanjutkan dengan pembuatan sampel uji silinder berukuran 15 cm x 30 cm (karakteristik kuat tekan, ketahanan sulfat), sampel uji prisma berukuran 20 cm x 20 cm x 12 cm (karakteristik permeabilitas) dan sampel uji kubus berukuran 15 cm x 15 cm x 15 cm (untuk penetrasi klorida). Pengamatan dilakukan untuk melihat karakteristik beton K250 dengan penambahan silica fume 10%, dibandingkan dengan beton normal sebagai acuan, serta aplikasinya dalam lingkungan normal maupun asam (Sulfat, Klor). Hasil kuat tekan memperlihatkan, bahwa campuran dengan menggunakan semen PCC memiliki nilai kuat tekan rata-rata diatas semen OPC. Penambahan silica fume pada campuran semen PCC akan menaikkan nilai kuat tekan sebesar 4,2% dibandingkan beton normal dengan produk semen yang sama, meskipun nilai rasio air-semen nya membesar menjadi 0,71 karena penambahan air. Nilai kuat tekan terbesar diperoleh untuk campuran beton dengan semen Tipe II. Campuran dengan semen PCC (2) menunjukkan nilai penetrasi yang lebih kecil dibandingkan campuran lainnya, hal ini mengindikasikan produk beton yang terbentuk memiliki kepadatan yang lebih baik dari produk campuran lainnya dan tidak porous, sehingga dapat dikatakan memiliki tingkat durabilitas yang cukup baik. Untuk ketahanan terhadap serangan sulfat, beton dengan menggunakan campuran semen tipe II mengalami tingkat pelapukan/penggerusan penampang (scaling) yang lebih besar dibandingkan campuran beton lainnya, meskipun begitu hal ini tidak mempengaruhi nilai kuat tekannya. Untuk produk dengan semen PCC, serangan sulfat tidak mempengaruhi nilai kuat tekannya, bahkan cenderung naik bila dibandingkan pada usia 28 hari.Kata kunci: aspek durabilitas, tipe semen, pemanfaatan silica fume

High Performance Concrete with Ternary Binders

2018 ◽  
Vol 761 ◽  
pp. 120-123 ◽  
Author(s):  
Vlastimil Bílek ◽  
David Pytlík ◽  
Marketa Bambuchova
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Silica Fume ◽  
High Performance ◽  
Ordinary Portland Cement ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Binder Ratio ◽  
Water To Binder Ratio ◽  
Condensed Silica Fume

Use a ternary binder for production of a high performance concrete with a compressive strengths between 120 and 170 MPa is presented. The water to binder ratio of the concrete is 0.225 and the binder is composed of Ordinary Portland Cement (OPC), condensed silica fume (CSF), ground limestone (L), fly ash (FA) and metakaoline (MK). The dosage of (M + CSF) is kept at a constant level for a better workability of fresh concrete. Different workability, flexural and compressive strengths were obtained for concretes with a constant cement and a metakaoline dosage, and for a constant dosage (FA + L) but a different ratio FA / L. An optimum composition was found and concretes for other tests were designed using this composition.

Effect of Heat Treatment on Properties of Portland Cement Pastes: Determination through Ultra-Microhardness Test

2015 ◽  
Vol 820 ◽  
pp. 492-496
Author(s):  
D.C.S. Garcia ◽  
Roberto Braga Figueiredo ◽  
Maria Teresa Paulino Aguilar
Keyword(s):  
Heat Treatment ◽  
Portland Cement ◽  
Optical Microscopy ◽  
Silica Fume ◽  
Ordinary Portland Cement ◽  
Cement Pastes ◽  
Microhardness Test ◽  
Material Hardness ◽  
Binder Ratio ◽  
Water Binder Ratio

The aim of this paper was to investigate the influence of heat treatment on hardness evolution of cement pastes containing silica fume. The specimens were prepared with Ordinary Portland Cement, water/binder ratio of 0,40 and 25% wt. silica fume. The specimens were cast at room temperatures and after 24 hours, they were placed in a furnace for 24 hours, with heat regimes of 100°C, 200°C and 300°C and then submitted to the ultra-microhardness test. The microstructure was analyzed using optical microscopy. The results showed that the silica fume prevents the production of calcium hydroxide and the heat treatment increases the material hardness.

scholarly journals Analysis of Chemical Composition of Portland Cement in Ghana: A Key to Understand the Behavior of Cement

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mark Bediako ◽  
Eric Opoku Amankwah
Keyword(s):  
Chemical Composition ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Chemical Compositions ◽  
Test Results ◽  
Brand Name ◽  
X Ray ◽  
Portland Limestone Cement ◽  
Limestone Cement ◽  
Construction Works

The performance of Portland cement in concrete or mortar formation is very well influenced by chemical compositions among other factors. Many engineers usually have little information on the chemical compositions of cement in making decisions for the choice of commercially available Portland cement in Ghana. This work analyzed five different brands of Portland cement in Ghana, namely, Ghacem ordinary Portland cement (OPC) and Portland limestone cement (PLC), CSIR-BRRI Pozzomix, Dangote OPC, and Diamond PLC. The chemical compositions were analyzed with X-Ray Fluorescence (XRF) spectrometer. Student’st-test was used to test the significance of the variation in chemical composition between standard literature values and each of the commercial cement brands. Analysis of variance (ANOVA) was also used to establish the extent of variations between chemical compositions and brand name of the all commercial Portland cement brands. Student’st-test results showed that there were no significant differences between standard chemical composition values and that of commercial Portland cement. The ANOVA results also indicated that each brand of commercial Portland cement varies in terms of chemical composition; however, the specific brands of cement had no significant differences. The study recommended that using any brand of cement in Ghana was good for any construction works be it concrete or mortar formation.

scholarly journals Development of Eco-Concrete Produced with Calcined Marl Clay as Cement Replacement Material

2021 ◽  
Vol 21 (4) ◽  
pp. 129-137
Author(s):  
Young-Min Kim ◽  
Ji-Su Kim ◽  
Tong-Seok Han
Keyword(s):  
Portland Cement ◽  
Co2 Emissions ◽  
Co2 Emission ◽  
Ordinary Portland Cement ◽  
Chemical Resistance ◽  
Raw Materials ◽  
Performance Difference ◽  
Test Results ◽  
Replacement Ratio ◽  
Cement Replacement

Because of the increase in greenhouse gas emissions and the enforcement of environmental regulations, efforts to reduce CO2 emissions continue. In this study, calcined marl clay was used as a cement replacement material to minimize CO2 emissions by reducing the cement amount used. The raw materials for marl clay were analyzed, and the durability and chemical resistance of concrete produced with marl clay were examined. From the test results, the optimum replacement ratio of calcined marl clay was determined, and the performance difference with ordinary Portland cement (OPC) concrete was identified. The performance of the eco-concrete was comparable to that of the OPC concrete containing marl clay when the cement was optimally replaced with marl clay. Furthermore, the CO2 emission for each specimen was calculated. This study demonstrated the feasibility of developing eco-friendly concrete using calcined marl clay.

scholarly journals Karakteristik Beton Portland Composite Cement (PCC) Dan Silica Fume Untuk Aplikasi Struktur di Daerah Laut

2019 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Dwi Susanto ◽  
Zulfikar Djauhari ◽  
Monita Olivia
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Ordinary Portland Cement ◽  
Composite Cement

Trend penggunaan semen untuk konstruksi dalam beberapa tahun belakangan ini telah beralih dari tipe Ordinary Portland Cement (OPC) menjadi Portland Composite Cement (PCC). Hal ini berdasarkan kebijakan industri semen untuk mengkonversi sebagian kandungan semen OPC menggunakan material pozzolanik. Oleh karena itu semen tipe PCC lebih mudah diperoleh di pasaran dan telah banyak digunakan sektor konstruksi dalam aplikasi di berbagai lingkungan meski belum banyak diteliti keunggulannya. Pada penelitian ini dikaji karakteristik beton semen PCC untuk aplikasi dermaga di daerah pasang-surut lingkungan air laut. Parameter penelitian adalah penambahan aditif silika dan umur beton yang direndam di air laut. Beton PCC dengan mutu beton fc’ = 30 MPa digunakan sebagai campuran kontrol, sedangkan beton PCC dengan tambahan silica fume (PCC+SF) sebesar Setelah benda uji dicetak, kemudian benda uji direndam di bak perendaman selama 3 hari dan diletakkan di daerah pasang-surut pelabuhan Belawan, Medan, Sumatera Utara hingga waktu pengujian. Pengujian yang dilakukan adalah kuat tekan, kuat tarik dan porositas setelah benda uji direndam dalam air laut pada umur 28, 91 dan 180 hari. Hasil pengujian menunjukkan bahwa umumnya kuat tekan dan kuat tarik meningkat serta porositas menurun untuk beton PCC dan PCC+SF meski direndam di daerah pasang-surut hingga umur 180 hari. Akan tetapi beton PCC+SF memiliki karakteristik lebih baik dibandingkan beton PCC dan direkomendasikan untuk beton terpapar air laut di daerah pasang-surut.

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