Fabrication and properties of 3-3 type PZT-ordinary Portland cement composites

2021 ◽  
Vol 305 ◽  
pp. 124815
Author(s):  
Wei Liu ◽  
Lehui Zhang ◽  
Yu Cao ◽  
Jianhong Wang ◽  
Peikang Bai ◽  
...  
2020 ◽  
Vol 106 ◽  
pp. 103488 ◽  
Author(s):  
Junlin Lin ◽  
Ezzatollah Shamsaei ◽  
Felipe Basquiroto de Souza ◽  
Kwesi Sagoe-Crentsil ◽  
Wen Hui Duan

RSC Advances ◽  
2018 ◽  
Vol 8 (49) ◽  
pp. 27602-27609
Author(s):  
Zhenzhou Yang ◽  
Ji Ru ◽  
Lili Liu ◽  
Xidong Wang ◽  
Zuotai Zhang

In order to evaluate the long-term environmental impact of Eco-Ordinary Portland Cement (EOPC) prepared by hazardous wastes, long-term leaching tests were conducted on the EOPC composites under deionized and saline water conditions.


Holzforschung ◽  
1999 ◽  
Vol 53 (1) ◽  
pp. 104-108 ◽  
Author(s):  
N. Sauvat ◽  
R. Sell ◽  
E. Mougel ◽  
A. Zoulalian

Summary As an essential preliminary to understand the hydration of wood-cement composites, the effects of some additives on the delayed setting due to wood of an Ordinary Portland Cement have been investigated by isothermal calorimetry. With the addition of calcium chloride and activated charcoal, an increase of 50% of the total enthalpy is observed in wood-cement composites hydration, because calcium chloride mostly influences aluminate phases and activated charcoal silicate phases.


2007 ◽  
Vol 61 (30) ◽  
pp. 5206-5208 ◽  
Author(s):  
A. Chaipanich ◽  
N. Jaitanong ◽  
T. Tunkasiri

2012 ◽  
Vol 2 (1) ◽  
pp. 25
Author(s):  
Ariyadi Basuki ◽  
Maulana Ikhwan Sadikin

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


2021 ◽  
Vol 19 (4) ◽  
pp. 315-328
Author(s):  
N.M. Khalil ◽  
Yousif Algamal

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).


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3467
Author(s):  
Ankit Kothari ◽  
Karin Habermehl-Cwirzen ◽  
Hans Hedlund ◽  
Andrzej Cwirzen

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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