Shear-thickening behavior of sustainable cement paste — Controlling physical parameters of new sources of supplementary cementitious materials

2021 ◽  
Vol 310 ◽  
pp. 125277
Author(s):  
Houssam Kemer ◽  
Rachid Bouras ◽  
Noureddine Mesboua ◽  
Mohammed Sonebi ◽  
Oliver Kinnane
Keyword(s):  
Cement Paste ◽  
Shear Thickening ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Physical Parameters ◽  
Thickening Behavior

Use of Algerian Natural Mineral Deposit as Supplementary Cementitious Materials

2018 ◽  
Vol 34 ◽  
pp. 48-58 ◽  
Author(s):  
Karima Arroudj ◽  
Saida Dorbani ◽  
Mohamed Nadjib Oudjit ◽  
Arezki Tagnit-Hamou
Keyword(s):  
Mechanical Strength ◽  
Calcium Hydroxide ◽  
Cement Paste ◽  
Cementitious Materials ◽  
Pozzolanic Reaction ◽  
Heat Of Hydration ◽  
Cement Industry ◽  
Supplementary Cementitious Materials ◽  
Natural Mineral ◽  
Different Ages

Much of the current research on concrete engineering has been focused on including siliceous additions as supplementary cementitious materials (SCMs). Silica reacts with Calcium hydroxide release during cement hydration, and produces more C-S-H. The latter contributes to increase compactness, mechanical strengths and sustainability of concrete. This paper explores the hydration characteristics of cement paste based on various natural mineral additions, that are very abundant in Algeria and present a high silica content (ground natural pozzolana “PZ” and ground dune sand “DS”). For this purpose, several analyses were carried out on modified cement pastes and mortars. TheseSCMswere introduced by replacement levels of 15, 20 and 25 by weight of cement. We first, studied the effect of these SCMs on the heat of hydration and mechanical strength of mortars at different ages. The evolution of hydration of modified paste was studied, by using Thermal analysis (TG/TDA) at different ages, to analyze the Calcium Hydroxide (CH) content of the modified pastes. It is shown that the CH content of the mixes including SCMs is lower than that of the plain cement paste, indicating that silica reacts with the cement paste through a pozzolanic reaction. Increased pozzolanic activity results in higher amounts of Calcium Silicate Hydrate in the paste, which in turn results in higher compressive strength for modified cement mortars. Due to its crystalline morphology, the ground DS particles present a partial pozzolanic effect, compared to PZ which is semi-crystalline. Modified mortars by 20% DS can be the optimal composition. It presents satisfactory results: good mechanical strength and low heat of hydration. It can lead to an economic and sustainable concrete. Ground DS is very abounded in Africa and free of any impurities and can be a good alternativeSCMsin cement industry.

Hydration Characteristics of Cement Paste Containing Supplementary Cementitious Materials

2012 ◽  
Vol 37 (3) ◽  
pp. 535-544 ◽  
Author(s):  
A. Elahi ◽  
Q. U. Z. Khan ◽  
S. A. Barbhuiya ◽  
P. A. M. Basheer ◽  
M. I. Russell
Keyword(s):  
Cement Paste ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Hydration Characteristics

scholarly journals Hydration–Strength–Workability–Durability of Binary, Ternary, and Quaternary Composite Pastes

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 204
Author(s):  
Yi Han ◽  
Seokhoon Oh ◽  
Xiao-Yong Wang ◽  
Run-Sheng Lin
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Carbon Emissions ◽  
Cementitious Materials ◽  
Heat Of Hydration ◽  
Surface Resistivity ◽  
Cement Industry ◽  
Supplementary Cementitious Materials ◽  
Limestone Powder ◽  
Alternative Materials

At present, reducing carbon emissions is an urgent problem that needs to be solved in the cement industry. This study used three mineral admixtures materials: limestone powder (0–10%), metakaolin (0–15%), and fly ash (0–30%). Binary, ternary, and quaternary pastes were prepared, and the specimens’ workability, compressive strength, ultrasonic pulse speed, surface resistivity, and the heat of hydration were studied; X-ray diffraction and attenuated total reflection Fourier transform infrared tests were conducted. In addition, the influence of supplementary cementitious materials on the compressive strength and durability of the blended paste and the sustainable development of the quaternary-blended paste was analyzed. The experimental results are summarized as follows: (1) metakaolin can reduce the workability of cement paste; (2) the addition of alternative materials can promote cement hydration and help improve long-term compressive strength; (3) surface resistivity tests show that adding alternative materials can increase the value of surface resistivity; (4) the quaternary-blended paste can greatly reduce the accumulated heat of hydration; (5) increasing the amount of supplementary cementitious materials can effectively reduce carbon emissions compared with pure cement paste. In summary, the quaternary-blended paste has great advantages in terms of durability and sustainability and has good development prospects.

Triple Blending with Superfine Natural Zeolite and Condensed Silica Fume to Improve Performance of Cement Paste

2017 ◽  
Author(s):  
P.L. Ng ◽  
J.J. Chen ◽  
A.K.H. Kwan
Keyword(s):  
Silica Fume ◽  
Cement Paste ◽  
Packing Density ◽  
Natural Zeolite ◽  
Water Film ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Concrete Production ◽  
Fine Size ◽  
Condensed Silica Fume

Superfine natural zeolite (SNZ) is obtained by grinding natural zeolite to micro-fine size, whereas condensed silica fume (CSF) is by-product of ferrosilicon industry. Both SNZ and CSF are environmentally-friendly supplementary cementitious materials for mortar and concrete production. Owing to the high fineness and favourable grading of SNZ and CSF (the median particle sizes were 4 μm and 0.4 μm, respectively), the addition of SNZ and CSF could successively fill the voids between ordinary Portland cement (OPC) grains and increase the packing density of the binder, so as to reduce the volume of voids to be filled with water. Therefore, triple blending of OPC+SNZ+CSF can benefit the overall performance of cement paste by releasing more water for flowability improvement at the same water/binder (W/B) ratio, or adopting a lower W/B ratio for strength improvement at the same flowability requirement. This study evaluated the effects of adding SNZ and CSF on the packing density and water film thickness of binder. The experimental results proved that triple blending with SNZ and CSF could increase the packing density and improve the flowability and cohesiveness of cementitious paste.

Effects of Condensed Silica Fume and Superfine Cement on Flowability of Cement Paste

2011 ◽  
Vol 121-126 ◽  
pp. 2695-2700 ◽  
Author(s):  
A. K. H. Kwan ◽  
Jia Jian Chen ◽  
L. G. Li
Keyword(s):  
Experimental Study ◽  
Silica Fume ◽  
Cement Paste ◽  
Water Film ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Definite Effect ◽  
Wide Range ◽  
Depth Analysis ◽  
Condensed Silica Fume

Addition of supplementary cementitious materials (SCM) has been contradictorily reported to be beneficial or detrimental to the flowability of concrete and no general conclusion can be drawn up to now. In order to comprehensively disclose the effects of SCM on the flowability, an experimental study had been carried out to measure the flowability of a total of 100 cement paste samples with different condensed silica fume (CSF) and superfine cement (SFC) contents at a wide range of water/cementitious materials (W/CM) ratios. The results showed that the addition of CSF would decrease the flowability at a relatively high W/CM ratio but increase the flowability at a low W/CM ratio, while the addition of SFC could generally improve the flowability of cement paste. Joint addition of SFC and CSF would not exert any definite effect on flowability at a relatively high W/CM ratio but could improve the flowability at a low W/CM ratio. In-depth analysis showed that these results could be well explained by the theory of water film thickness.

scholarly journals The impact of metakaolin, silica fume and fly ash on the temperature resistance of high strength cement paste

2021 ◽  
Author(s):  
Nabil Abdelmelek ◽  
Eva Lubloy
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Cement Paste ◽  
Elevated Temperatures ◽  
High Strength ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Temperature Resistance ◽  
Maximum Temperatures ◽  
The Impact

AbstractThe effects of elevated temperatures on the properties of high-strength cement paste (HSCP) based on metakaolin (MK), silica fume (SF), and fly ash (FA) were studied in the current experimental research. The resistance of HSCP against elevated temperatures was evaluated as well. The new method is expressed by the total area under each curve of strength, known as “temperature resistance”, is adopted. Results of the HSCP mixtures containing MK, SF, and FA with replacements ratios of 9%, 6% and 15% have shown excellent temperature resistance at all levels of maximum temperatures, respectively. Properties added to HSCP by these supplementary cementitious materials (SCM) such as decreasing the amount of CaO and increasing the amounts of SiO2 and Al2O3 have minimized the harmful effects of the use of pure ordinary Portland cement (OPC) at elevated temperatures. The results have shown also that the grinding fineness of OPC influences the amount of optimum replacement of the used SCM on HSCP at elevated temperatures. Hence, the amount of optimum replacement of MK blended with CEM I 42.5 N was 9% whereas, the amount of optimum replacement of MK blended with CEM I 52.5 N shifted to 3%. Finally, the fineness of cement of 4500 cm2 g−1 has shown a better-elevated temperature resistance compared to the cement with a fineness of 4000 cm2 g−1 in case of using pure OPC.

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