scholarly journals Use of clay from a local source for calcination and subsequent preparation of the mixed cement

2021 ◽  
Vol 1205 (1) ◽  
pp. 012005
Author(s):  
B Smirova ◽  
M Sedlacik ◽  
R Novotny
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Mechanical Strength ◽  
Cementitious Materials ◽  
Pozzolanic Activity ◽  
Supplementary Cementitious Materials ◽  
Hydration Process ◽  
Local Source ◽  
Optimal Ratio ◽  
Initial Decrease

Abstract This paper deals with the use of calcinated clay and micronized limestone as supplementary cementitious materials (SMCs) for preparation of blended Portland cement CEM II/B-M (Q-LL). Clay used in this study was calcinated at 700°C and pozzolanic activity after calcination was assessed using accelerated R3 pozzolanic test and modified Chapelle test. The influence of calcinated clay and limestone addition on mechanical properties and hydration process was investigated and an optimal ratio for 35% clinker replacement was found. Initial decrease of mechanical strength at early ages, caused by SCM addition, was almost compensated during maturation of the binder.

Research Progress on the Hydration of Portland Cement with Calcined Clay and Limestone

2021 ◽  
Vol 1036 ◽  
pp. 240-246
Author(s):  
Jin Tang ◽  
Su Hua Ma ◽  
Wei Feng Li ◽  
Hui Yang ◽  
Xiao Dong Shen
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Research Progress ◽  
Hydration Reaction ◽  
Hydration Products ◽  
Early Hydration ◽  
Calcined Clay ◽  
Dense Microstructure

The use of calcined clay and limestone as supplementary cementitious materials, can have a certain influence on the hydration of Portland cement. This paper reviewed the influence of limestone and calcined clay and the mixture of limestone and calcined clay on the hydration of cement. Both limestone and calcined clay accelerate the hydration reaction in the early hydration age and enhance the properties of cement. Limestone reacts with C3A to form carboaluminate, which indirectly stabilized the presence of ettringite, while calcined clay consumed portlandite to form C-(A)-S-H gel, additional hydration products promote the densification of pore structure and increase the mechanical properties. The synergistic effect of calcined clay and limestone stabilize the existence of ettringite and stimulate the further formation of carboaluminate, as well as the C-(A)-S-H gel, contributed to a dense microstructure.

scholarly journals Measurement of Pozzolanic Activity Index of Scoria, Pumice, and Rice Husk Ash as Potential Supplementary Cementitious Materials for Portland Cement

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Hieronimi A. Mboya ◽  
Cecil K. King’ondu ◽  
Karoli N. Njau ◽  
Alex L. Mrema
Keyword(s):  
Portland Cement ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Activity Index ◽  
Cementitious Materials ◽  
Pozzolanic Activity ◽  
Supplementary Cementitious Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Setting Times

This work investigated the properties of scoria and pumice as supplementary cementitious materials (SCMs) for Portland cement and compared to those of rice husk ash (RHA). X-ray fluorescence, X-ray diffraction, and pozzolanic activity index (PAI) tests confirmed the suitability of these two materials as potential SCMs. Scoria and RHA samples achieved over 75% PAI at 7 days whereas pumice did this after 28 days. Initial and final mean setting times observed for the composite cement blended with these materials were 166 and 285 min, respectively. These setting times are longer than that of ordinary Portland cement but shorter compared to that of common Portland pozzolana cement. The ultimate mean compressive strengths achieved at 28 days of curing were 42.5, 44.8, and 43.0 MPa for scoria, pumice, and RHA, respectively, signifying that these materials are good SCMs. Higher fineness yielded higher ultimate mean strength. For instance, a scoria sample with a fineness of 575 m2/kg achieved the strength of 52.2 MPa after 28 days.

Assessment of Raw Mineral Waste as Building Materials in Developing Countries

2018 ◽  
Vol 40 ◽  
pp. 30-46
Author(s):  
Njarazo Rakotondrabezaharinoro ◽  
Moutari Ado ◽  
Willy Hermann Juimo Tchamdjou
Keyword(s):  
Mechanical Properties ◽  
Developing Countries ◽  
Portland Cement ◽  
Building Materials ◽  
Raw Materials ◽  
Activity Index ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Cement Replacement ◽  
Mineral Waste

In many developing country’s mining exploitations are the main activities sources, and its exploitation is generating many mining wastes and environmental impacts. In order to use these waste, an innovative powder and aggregate were designed, aimed at providing alternative materials by cementitious supplementary materials and sand in Portland cement mortars. This paper investigates the use of raw mineral waste from some developing countries, namely Granite Residue (GR), from Niger, Mining Tailings (MT), from Madagascar, and red Volcanic Scoria (VS), from Cameroon as building materials. These raw materials were valorized as supplementary cementitious materials (GR powder, MS powder and VS powder) and as sand (GR sand and VS sand). GR sand and VS sand were used by 100% replacement of standard sand and GR powder, MS powder and VS powder were used by 5, 15, 25, or/and 35% cement replacement. Physical properties and mechanical properties of raw materials used and mortars obtained were investigated. The effects of these raw materials on properties of mortar mixes were studied and reported. Results show that, with sand from raw mineral waste materials, the compressive and flexural strengths of the produced mortar represented up than 70% and up than 85% respectively in comparison with mortar produce with siliceous standard sand. The reduction of strength of mortar with raw powder as ordinary Portland cement replacement is generally smaller than replacement ratio. Activity index of each raw powder is about 75% for ratio replacement of 5, 15 and 25%. Particle size distribution of raw powder and sand have an influence on the workability and mechanical properties of mortars. In conclusion, the use of raw mineral waste as a raw powder or as sand for mortar production presents an economical and environmental advantage for developing countries where mining exploitations are abundant.

scholarly journals Assessment of the pozzolanic activity of ornamental stone waste after heat treatment and its effect on the mechanical properties of concretes

2018 ◽  
Vol 11 (6) ◽  
pp. 1186-1207 ◽  
Author(s):  
S. H. M. MITTRI ◽  
M. K. DEGEN ◽  
G. L. VIEIRA ◽  
J. S. VAZZOLER ◽  
L. H. C. H. RODRIGUES
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Portland Cement ◽  
Mechanical Strength ◽  
Physical Characteristics ◽  
Pozzolanic Activity ◽  
Processing Waste ◽  
Ornamental Stone ◽  
Pozzolanic Materials ◽  
Pozzolanic Properties

Abstract This paper aims at evaluating the pozzolanic properties of ornamental stone processing waste after heat treatment at 1200 °C (HTOSPW) and analyzing the influence on the mechanical strength of concrete produced with HTOSPW addition at the contents of 5% and 10% by mass of Portland cement. The HTOSPW shows promising results regarding the pozzolanic activity, revealing chemical and physical characteristics typical of pozzolanic materials in addition to being approved in the pozzolanicity tests performed. As for the concretes produced with HTOSPW addition, a significant increase in mechanical strength was observed, especially for concretes with a 10% addition.

Evaluation of strength of concrete on different initial exposure condition

2020 ◽  
Vol 13 ◽  
Author(s):  
Sri Ram Krishna Mishra ◽  
Pradeep Kumar Ghosh ◽  
Manoj Kulshreshtha
Keyword(s):  
Portland Cement ◽  
High Strength ◽  
Cementitious Materials ◽  
General Purpose ◽  
Supplementary Cementitious Materials ◽  
Exposure Condition ◽  
Portland Cement Concrete ◽  
Initial Exposure ◽  
Skilled Manpower ◽  
Standard Practices

Background: The previous studies have focused curing effect of mainly on high strength concrete, where strict supervision is maintained. This study is based upon general purpose concreting work for commercial and residential construction in absence of skilled manpower and supervision. Objective: The objective of this study is to establish a thumb rule to provide 7 days initial curing for maintaining quality for unsupervised concreting irrelevant to type of cement and grading. Methods: In this study concrete samples made with locally available commercial cements were cured for various initial exposure. Results: The results shows that concrete cured after a gap of 4 days from the time of de-moulding have given lowest strength as compared to concrete cured in standard practices i.e. where proper curing protocol had been followed. Conclusion: Initial curing is most important aspect of gaining desired strength. The findings after this study shows that curing affects the strength of concrete in variable grading. Initial curing has great importance for concrete with all types of Portland cement. Concrete with supplementary cementitious materials gives lowest strength initially but results higher strength after 28 days as compared to Portland cement.

scholarly journals Special Issue: Supplementary Cementitious Materials in Concrete, Part I

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2291
Author(s):  
Alessandro P. Fantilli ◽  
Daria Jóźwiak-Niedźwiedzka
Keyword(s):  
Environmental Impact ◽  
Portland Cement ◽  
Building Materials ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Special Issue ◽  
Cement Production ◽  
Concrete Part

The environmental impact of the Portland cement production and the large use of cement-based building materials is a growing problem [...]

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.

scholarly journals The Potentials of Iron and Steel Slags as Supplementary Cementitious Materials in the Nigerian Construction Industry: A Review

2018 ◽  
Vol 2 (2) ◽  
pp. 208-218
Author(s):  
O. R. Ogirigbo ◽  
J. O. Ukpata ◽  
I. Inerhunwa
Keyword(s):  
Portland Cement ◽  
Construction Industry ◽  
Waste Product ◽  
Steel Production ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Partial Replacement ◽  
Iron And Steel ◽  
Tropical Environments ◽  
Iron And Steel Production

Ground Granulated Blast Furnace Slag (GGBS) is a type of Supplementary Cementitious Material (SCM) that is currently being used extensively in the global construction industry. SCMs are cheaper than Portland cement, help to improve certain properties of concrete and also help to reduce the environmental footprint associated with the production of Portland cement. GGBS is readily available in most parts of the world as a waste product from iron and steel production. However, its use as a SCM in some countries has not been fully maximized. This is primarily because of lack of documented studies on the properties of GGBS that influences its suitability as a SCM, especially in tropical environments. This paper reviewed the use of GGBS as a SCM for the partial replacement of Portland cement, with particular emphasis on its potential use in tropical warm environments such as Nigeria and other similar countries.

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.

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