The effects of Graphene Oxide addition on hydration process, crystal shapes, and microstructural transformation of Ordinary Portland Cement

2020 ◽  
Vol 32 ◽  
pp. 101551 ◽  
Author(s):  
Karthik Chintalapudi ◽  
Rama Mohan Rao Pannem
Keyword(s):  
Graphene Oxide ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Hydration Process ◽  
Crystal Shapes ◽  
Oxide Addition ◽  
Microstructural Transformation

Characterization of the Initial Hydration Process of Ordinary Portland Cement Based on Low-Field NMR

2018 ◽  
Vol 50 (1-3) ◽  
pp. 187-198
Author(s):  
Jin-hua Huo ◽  
Zhi-gang Peng ◽  
Zhongbin Ye ◽  
Qian Feng ◽  
Yong Zheng ◽  
...  
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Hydration Process ◽  
Low Field ◽  
Low Field Nmr

scholarly journals Physical Properties of Concrete Containing Graphene Oxide Nanosheets

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1707 ◽  
Author(s):  
Yu-You Wu ◽  
Longxin Que ◽  
Zhaoyang Cui ◽  
Paul Lambert
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Graphene Oxide ◽  
Flexural Strength ◽  
Portland Cement ◽  
Physical Properties ◽  
Ordinary Portland Cement ◽  
Construction Materials ◽  
Split Tensile Strength ◽  
Cement Pastes

Concrete made from ordinary Portland cement is one of the most widely used construction materials due to its excellent compressive strength. However, concrete lacks ductility resulting in low tensile strength and flexural strength, and poor resistance to crack formation. Studies have demonstrated that the addition of graphene oxide (GO) nanosheet can effectively enhance the compressive and flexural properties of ordinary Portland cement paste, confirming GO nanosheet as an excellent candidate for using as nano-reinforcement in cement-based composites. To date, the majority of studies have focused on cement pastes and mortars. Only limited investigations into concretes incorporating GO nanosheets have been reported. This paper presents an experimental investigation on the slump and physical properties of concrete reinforced with GO nanosheets at additions from 0.00% to 0.08% by weight of cement and a water–cement ratio of 0.5. The study demonstrates that the addition of GO nanosheets improves the compressive strength, flexural strength, and split tensile strength of concrete, whereas the slump of concrete decreases with increasing GO nanosheet content. The results also demonstrate that 0.03% by weight of cement is the optimum value of GO nanosheet dosage for improving the split tensile strength of concrete.

Dispersion of graphene oxide–silica nanohybrids in alkaline environment for improving ordinary Portland cement composites

2020 ◽  
Vol 106 ◽  
pp. 103488 ◽  
Author(s):  
Junlin Lin ◽  
Ezzatollah Shamsaei ◽  
Felipe Basquiroto de Souza ◽  
Kwesi Sagoe-Crentsil ◽  
Wen Hui Duan
Keyword(s):  
Graphene Oxide ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Cement Composites ◽  
Alkaline Environment

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

Utilization of petroleum sludge wastes for increasing productivity of ordinary portland cement

2021 ◽  
Vol 19 (4) ◽  
pp. 315-328
Author(s):  
N.M. Khalil ◽  
Yousif Algamal
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Production Capacity ◽  
Hydration Product ◽  
High Energy ◽  
Cement Industry ◽  
Blended Cements ◽  
Petroleum Waste ◽  
Waste Sludge ◽  
Suitable Amount

This work aims at maximum exploitation of petroleum waste sludge as additive to portland cement to prepare blended cements and hence increasing its production capacity without further firing. This will decrease the main cement industry problems involving environmental pollution such as releasing gases and high-energy consumption during industry and hence maximizes the production economics. Six batches of ordinary portland cement (OPC) mixed with different proportions of petroleum waste sludge (PWS) donated as C1 (control batch contains no PWS), C2 (contains 90 wt.% of OPC+10 wt.% of PWS), C3 (contains 80 wt.% of OPC+20 wt.% of PWS), C4 (contains 70 wt.% of OPC+30 wt.% of PWS), C4 (contains 60 wt.% of OPC+40 wt.% of PWS) and C6 (contains 50 wt.% of OPC+50 wt.% of PWS), were prepared and mixed individually with the suitable amount of mixing water. Cement mixes C2, C3 and C4 showed improved cementing and physicomechanical properties compared with pure cement (C1) with special concern of mix C4. Such improvement is due to the relatively higher surface area as well as the high content of kaolinite and quartz in the added PWS (high pozzalanity) favoring the hydration process evidenced by the increase in the cement hydration product (portlandite mineral (Ca (OH) 2).

scholarly journals A Review of the Mechanical Properties and Durability of Ecological Concretes in a Cold Climate in Comparison to Standard Ordinary Portland Cement-Based Concrete

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3467
Author(s):  
Ankit Kothari ◽  
Karin Habermehl-Cwirzen ◽  
Hans Hedlund ◽  
Andrzej Cwirzen
Keyword(s):  
Carbon Dioxide ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Cementitious Materials ◽  
Cold Climate ◽  
Supplementary Cementitious Materials ◽  
Short Exposure ◽  
Chemical Admixtures ◽  
Composite Cements ◽  
Alkali Activated

Most of the currently used concretes are based on ordinary Portland cement (OPC) which results in a high carbon dioxide footprint and thus has a negative environmental impact. Replacing OPCs, partially or fully by ecological binders, i.e., supplementary cementitious materials (SCMs) or alternative binders, aims to decrease the carbon dioxide footprint. Both solutions introduced a number of technological problems, including their performance, when exposed to low, subfreezing temperatures during casting operations and the hardening stage. This review indicates that the present knowledge enables the production of OPC-based concretes at temperatures as low as −10 °C, without the need of any additional measures such as, e.g., heating. Conversely, composite cements containing SCMs or alkali-activated binders (AACs) showed mixed performances, ranging from inferior to superior in comparison with OPC. Most concretes based on composite cements require pre/post heat curing or only a short exposure to sub-zero temperatures. At the same time, certain alkali-activated systems performed very well even at −20 °C without the need for additional curing. Chemical admixtures developed for OPC do not always perform well in other binder systems. This review showed that there is only a limited knowledge on how chemical admixtures work in ecological concretes at low temperatures and how to accelerate the hydration rate of composite cements containing high amounts of SCMs or AACs, when these are cured at subfreezing temperatures.

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