scholarly journals Modelling the mechanical strength development of treated fine sediments: a statistical approach

2018 ◽  
Vol 40 (14) ◽  
pp. 1890-1909
Author(s):  
Ishak Moghrabi ◽  
Harifidy Ranaivomanana ◽  
Fateh Bendahmane ◽  
Ouali Amiri ◽  
Daniel Levacher
Keyword(s):  
Mechanical Strength ◽  
Statistical Approach ◽  
Strength Development ◽  
Fine Sediments

scholarly journals A rheometry method to assess the evaporation-induced mechanical strength development of polymer solutions used for membrane applications

2018 ◽  
Vol 136 (6) ◽  
pp. 47038 ◽  
Author(s):  
Eduard Caicedo-Casso ◽  
Jessica Sargent ◽  
Rachel M. Dorin ◽  
Ulrich B. Wiesner ◽  
William A. Phillip ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Polymer Solutions ◽  
Strength Development

scholarly journals Influence Of Volcanic Scoria On Mechanical Strength, Chemical Resistance And Drying Shrinkage Of Mortars

2014 ◽  
Vol 61 (3) ◽  
pp. 143-150 ◽  
Author(s):  
A. Al-Swaidani ◽  
S. Aliyan ◽  
N. Adarnaly ◽  
B. Hanna ◽  
E. Dyab
Keyword(s):  
Mechanical Strength ◽  
Sulphuric Acid ◽  
Chemical Resistance ◽  
Control Sample ◽  
Acid Resistance ◽  
Drying Shrinkage ◽  
Strength Development ◽  
Acid Solutions ◽  
Test Results ◽  
Blended Cements

Abstract In the study, three types of cement have been prepared; one CEM I type (the control sample) and two blended cements: CEM II/A-P and CEM II/B-P (EN 197-1), each of them with three replacement levels of volcanic scoria: (10 %, 15 %, 20 % wt.) and (25 %, 30 %, 35 % wt.), respectively. Strength development of mortars has been investigated at 2, 7, 28 and 90 days curing. Evaluation of chemical resistance of mortars containing scoria-based cements has been investigated through exposure to 5 % sulphate and 5 % sulphuric acid solutions in accordance with ASTM C1012 & ASTM 267, respectively. Drying shrinkage has been evaluated in accordance with ASTM C596. Test results showed that at early ages, the mortars containing CEM II/B-P binders had strengths much lower than that of the control mortar. However, at 90 days curing, the strengths were comparable to the control mortar. In addition, the increase of scoria significantly improved the sulphate resistance of mortars. Further, an increase in scoria addition improved the sulphuric acid resistance of mortar, especially at the early days of exposure. The results of drying shrinkage revealed that the CEM II/B-P mortar bars exhibited a greater contraction when compared to the control mortar, especially at early ages. However, drying shrinkage of mortars was not influenced much at longer times.

Statistical Approach to Analyze the Warpage, Shrinkage and Mechanical Strength of Injection Molded Parts

2016 ◽  
Vol 31 (3) ◽  
pp. 376-384 ◽  
Author(s):  
N. Hadler Marins ◽  
F. Bier de Mello ◽  
R. Marques e Silva ◽  
F. Aulo Ogliari
Keyword(s):  
Mechanical Strength ◽  
Statistical Approach ◽  
Molded Parts ◽  
Injection Molded

Effects of Various Amounts of Natural Pozzolans from Volcanic Scoria on Performance of Portland Cement Mortars

2017 ◽  
Vol 32 ◽  
pp. 36-52 ◽  
Author(s):  
Willy Hermann Juimo Tchamdjou ◽  
Sophie Grigoletto ◽  
Frédéric Michel ◽  
Luc Courard ◽  
Toufik Cherradi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Portland Cement ◽  
Mechanical Strength ◽  
Calcium Hydroxide ◽  
Supplementary Cementitious Materials ◽  
Strength Development ◽  
Natural Pozzolan ◽  
X Ray ◽  
Natural Pozzolans ◽  
Cement Mortars

The aim of this paper is to assess the possibility of using natural pozzolans (NPs) from Cameroonian volcanic scoria as supplementary cementitious materials (SCMs) in the production of Portland cement mortars. Four natural pozzolans (Black Natural Pozzolan: BNP, Dark-Red Natural Pozzolan: DRNP, Red Natural Pozzolan: RNP and Yellow Natural Pozzolan: YNP) with 3600, 4500, 4700 and 5200 cm2/g Blaine fineness respectively were produced from different colors (Black, Dark red, Red and Yellow) volcanic scoria in a laboratory mill. Natural pozzolans were characterized with regard to particle size distribution, particle shape, electrical conductivity, X-ray fluorescence (XRF) and X-ray diffraction (XRD). The calcium hydroxide consumption by NPs was assessed firstly by electrical conductivity measurements of calcium hydroxide/NPs suspensions with calcium hydroxide excess. Evidence of pozzolanic reactivity of NPs is revealed in hydrated lime pastes, and low reactivity was observed in aqueous suspensions. The effects of 15, 25, and 35 wt.% of NPs as cement substitution on the properties of Portland cement mortars were investigated. Different properties were studied such as setting time, consistency, mechanical strength, pozzolanic activity, absorption by capillarity and resistance to carbonation. The reactivity of NPs was also assessed by means of the mechanical strength development of mortars. The results obtained show that pozzolanic and hydraulic reactions take place in OPC systems. The correlation between mechanical strengths and physical properties of NPs has been established. The study concludes that using DRNP and RNP at 15 wt. % cement replacement can ameliorate globally the performance of mortar. Using all NPs at 35 wt. % has negative effect on the fundamental properties of cementitious mortars.

Preparation and Mechanical Properties of Potassium Metakaolin Based Geopolymer Paste

2019 ◽  
Vol 31 ◽  
pp. 38-45
Author(s):  
Hiep Le Chi ◽  
Petr Louda ◽  
Totka Bakalova ◽  
Vladimír Kovačič
Keyword(s):  
Compressive Strength ◽  
Mechanical Strength ◽  
Potassium Hydroxide ◽  
Silicate Solution ◽  
Curing Temperature ◽  
Polymerization Process ◽  
Strength Development ◽  
Early Age ◽  
Molar Ratios ◽  
Additional Water

In this study, geopolymer samples were prepared by mixing metakaolin (MA) with activator solution made of potassium alkali silicate solution, potassium hydroxide flakes, and additional water. The aim of the experiment is to evaluate the mechanical strength of hardened samples based on four test variables including the SiO2/K2O molar ratios, K2O concentration, H2O/MA water coefficient, and curing temperature. The results reveal that K2O concentration and H2O/MA water coefficient impact strongly on the compressive strength, whereas varying of SiO2/K2O molar ratios in the range from 1.0 – 1.4 does not significantly change the compressive strength of geopolymer samples. On the other hand, high-temperature curing leads to higher mechanical strength of the samples in the early-age compared to curing at room temperature, due to the faster establishment of hard structure in the early-age of geo-polymerization process. However, curing at a temperature range of 80°C – 100°C contributes the non-linear strength development of the samples over the time.

scholarly journals Effect of Bogue Potential Phases of Clinker on the Mechanical Strength of Fly ash-Limestone Based Portland Composite Cement

2021 ◽  
Vol 2 (2) ◽  
pp. 1-6
Author(s):  
B N Mohapatra
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Natural Resources ◽  
Mechanical Strength ◽  
Cementitious Materials ◽  
Strength Development ◽  
Blended Cements ◽  
Current Production ◽  
Increasing Demand

Continuous rise in population coupled with infrastructural requirements leads to increasing demand of cement which is projected to be around 4.8 billion tons by 2030 and 6.0 billion tons annually by 2050 from current production level of more than 4.2 billion tons [1], and this further requires judicious use of natural resources, particularly limestone on one side and to mitigate carbon and energy footprints on other for sustainable development. Therefore, to bring down environmental impact during cement production, cement industries have been engaged over the years to substitute Portland cement with alternative cementitious materials; fly ash, granulated blast furnace slag, limestone etc individually or in combination of two-three mineral constituents in the manufacture of blended cements, which showed better durability characteristics in comparison to ordinary Portland cement. The formulation and commercialisation of these cements largely depends on the quality of Portland clinkers in terms of oxide constituents, potential as well as actual phase composition, morphology and granulometry of alite and belite grains, along with availability and quality of the cementing materials, prevalent standard norms and regulations. In view of above, present paper highlights the effect of different clinkers in terms of potential minerals as per Bogue calculations (CL-1:C3S-48.20%, C3A-6.30%; CL-2:C3S-54.20%, C3A-9.30% and CL-3: C3S-60.05%, C3A-9.0%) on mechanical strength of fly ash-limestone based ternary cement blends, Portland composite cements, similar to CEM-II/A, B-M as per EN-197-1, prepared with 15, 20, 25, 30 and 35% by weight fly ash and 5 & 10% by weight limestone, by inter-grinding of all cement constituents process, maintaining Blaine’s fineness at 370±10m2/kg, and the results of compressive strength at different curing ages showed optimum strength development in case of clinker CL-2 with potential phases, C3S-54.20% and C3A-9.30%, thus leading to better management of natural resources and extended mine life.

Sign in / Sign up

Export Citation Format

Share Document