Investigation of Pozzolanic Binders Containing Calcined Laterites

1991 ◽  
Vol 245 ◽  
Author(s):  
Jean Pera ◽  
Jean Ambroise ◽  
Ali Sadr Momtazi
Keyword(s):  
Compressive Strength ◽  
Calcium Hydroxide ◽  
Pozzolanic Activity ◽  
Replacement Level ◽  
Blended Cements ◽  
Lime Reactivity

ABSTRACTWhen heated at 750°C for five hours, African laterites show good pozzolanic activity. The kaolin content of the materials affects their pozzolanicity as indicated by lime reactivity. Blended cements containing 20, 30, 40, and 50% calcined laterite admixture were examined.The rate of hydration was studied from compressive strength up to 90 days of curing and the hydrates formed as measured by DTA and XRD. The burnt laterite addition considerably reduced calcium hydroxide content and contributed to the formation of hydrated gehlenite (C2 ASH8) and gismondine (CASH).The best compressive streng hs were obtained with blended cements containing 30% calcined laterite. In some cases, there was no more portlandite in binders where the replacement level of cement by burnt laterite was 50% by mass.

scholarly journals Complex Characterization and Behavior of Waste Fired Brick Powder-Portland Cement System

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1650 ◽  
Author(s):  
Viviana Fátima Rahhal ◽  
Mónica Adriana Trezza ◽  
Alejandra Tironi ◽  
Claudia Cristina Castellano ◽  
Milena Pavlíková ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Dilution Effect ◽  
Pozzolanic Activity ◽  
Mineral Admixtures ◽  
Blended Cements ◽  
Ceramic Waste ◽  
Brick Powder ◽  
Cement System ◽  
And Performance

Two waste fired brick powders coming from brick factories located in Argentine and Czech Republic were examined as alternative mineral admixtures for the production of blended cements. In pastes composition, local Portland cements (Argentine and Czech) were substituted with 8–40%, by mass, with powdered ceramic waste. For the ceramic waste-Portland cement system, workability, the heat released, pozzolanity, specific density, compressive strength, hydrated phases, porosity, and pore size distribution were tested. The relevance of the dilution effect, filler effect, and pozzolanic activity was analyzed to describe the general behavior of the pozzolan/cement system. The properties and performance of cement blends made with finely ground brick powder depended on the composition of ceramic waste and its reactivity, the plain cement used, and the replacement level. Results showed that the initial mini-slump was not affected by a low ceramic waste replacement (8% and 16%), and then it was decreased with an increase in the ceramic waste content. Brick powder behaved as a filler at early ages, but when the hydration proceeded, its pozzolanic activity consumed partially the calcium hydroxide and promoted the formation of hydrated calcium aluminates depending on the age and present carbonates. Finally, blended cements with fired brick powder had low compressive strength at early ages but comparable strength-class at later age.

scholarly journals Hydration of Calcium Sulfoaluminate-Based Binder Incorporating Red Mud and Silica Fume

2019 ◽  
Vol 9 (11) ◽  
pp. 2270 ◽  
Author(s):  
Yubin Jun ◽  
Jae Hong Kim ◽  
Taewan Kim
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
Red Mud ◽  
Drying Shrinkage ◽  
Pozzolanic Activity ◽  
Main Reaction ◽  
Main Reaction Product ◽  
Replacement Level ◽  
Calcium Sulfoaluminate ◽  
Expansive Agent

This study investigated the properties of hardened pastes made with calcium sulfoaluminate expansive agent (CSA), red mud, and silica fume. Five different ratios of 10:90, 20:80, 30:70, 40:60, and 50:50 were applied as the weight ratios of CSA and red mud. Red mud was replaced with 0, 5, and 10% silica fume by weight. Compressive strength, drying shrinkage, XRD, MIP, and SEM/EDS of the hardened pastes were performed. The results indicated that as the amount of CSA increased (i.e., as the amount of red mud decreased) up to 30%, sample strengths showed a tendency to increase. The main reaction product of the pastes was expansive ettringite, which was formed from the consumption of ye’elimite, anhydrite, gypsum, and Ca(OH)2. It was expected that C-S-H would be formed by the reaction of C2S in red mud; however, C-S-H phase was not present, and the pozzolanic activity due to the use of silica fume did not occur. The increase of CSA replacement level was effective for controlling the drying shrinkage of the samples. However, 50% replacement level of CSA induced excessive expansion, leading to the reduction in strength. It was found that the excessive expansion in the sample was reduced by the addition of silica fume.

scholarly journals Pozzolanic activity of argentine vitreous breccia containing mordenite

2020 ◽  
Vol 70 (337) ◽  
pp. 208
Author(s):  
V. L. Bonavetti ◽  
V. F. Rahhal ◽  
F. Locati ◽  
E. F. Irassar ◽  
S. Marfil ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Activity Index ◽  
Staining Technique ◽  
Pozzolanic Reaction ◽  
Exchange Capacity ◽  
Pozzolanic Activity ◽  
Raw Material ◽  
Blue Staining ◽  
Early Hydration ◽  
Blended Cements

A vitreous breccia with variable amount of mordenite was studied for its use as pozzolan. The raw material was characterized by optical and scanning electron microscopy (SEM), X-ray diffraction (XRD), and the zeolite content was estimated by the methylene blue staining technique. After being ground, physical characteristics, cation exchange capacity (CEC), pozzolanicity, and the compressive strength activity index (SAI) were determined. The staining technique and the CEC measurement were used to evaluate the average content of zeolite. The vitreous breccia has pozzolanic activity after 7 days, the water demand increases slightly, and its addition stimulates the early hydration of portland cement. At later ages, the pozzolanic reaction around the grains, as revealed by SEM studies, improves the compressive strength of blended cements having a SAI > 0.85 at 28 days.

scholarly journals Portland blended cements: demolition ceramic waste management

2017 ◽  
Vol 67 (325) ◽  
pp. 114 ◽  
Author(s):  
M. A. Trezza ◽  
S. Zito ◽  
A. Tironi ◽  
E. F. Irassar ◽  
V. F. Rahhal
Keyword(s):  
Compressive Strength ◽  
Cementitious Materials ◽  
Pozzolanic Activity ◽  
Supplementary Cementitious Materials ◽  
Early Age ◽  
Blended Cements ◽  
Ceramic Waste ◽  
Materials Used ◽  
Potential Use

Demolition ceramic wastes (DCWs) were investigated in order to determine their potential use as supplementary cementitious materials in Portland Blended Cements (PBCs). For this purpose, three ceramic wastes were investigated. After characterization of the materials used, the effect of ceramic waste replacement (8, 24 and 40% by mass) was analyzed. Pozzolanic activity, hydration progress, workability and compressive strength were determined at 2, 7 and 28 days. The results showed that the ground wastes behave as filler at an early age, but as hydration progresses, the pozzolanic activity of ceramic waste contributes to the strength requirement.

The Effect of Substituting Rdf on the Physical and Environmental Properties of Coal Fly Ash

1988 ◽  
Vol 136 ◽  
Author(s):  
Ashaari B. Mohamad ◽  
David L. Gress
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Physical Properties ◽  
Activity Index ◽  
Coal Fly Ash ◽  
Pozzolanic Activity ◽  
Portland Cement Concrete ◽  
Fly Ash Concrete ◽  
Refuse Derived Fuel ◽  
Cadmium And Lead

ABSTRACTRefuse-derived-fuel (RDF) consisting mainly of waste paper and plastics is a viable fuel source for the production of power. An experimental test burn partially substituting coal with RDF was undertaken by the Public Service of New Hampshire at the Merrimack Power Station.Five percent and ten percent RDF were substituted, on a BTU basis, for coal in the test bums. The chemical and physical properties of the resulting fly ash were determined. Twelve test burn days were run with 4 days of 5% RDF and 8 days of 10% RDF. Emphasis was placed on investigating the effect of the RDF fly ash on Portland cement concrete.Most of the chemical and physical properties of the coal-RDF fly ash were found to be comparable with ordinary coal fly ash except for the amount of cadmium and lead, the pozzolanic activity index and the compressive strength of fly ash concrete. Cadmium and lead were at average levels of 5.1 ppm and 102.6 ppm for the 5% RDF, and 7.8 ppm and 198.3 ppm for the 10% RDF, respectively. Although the pozzolanic activity index of coal-RDF fly ash increases over normal coal fly ash, preliminary results show that the 28-day compressive strength of concrete with direct replacement of cement and sand decreases by up to 30%. Leaching tests on crushed concrete were conducted to evaluate the environmental effect of acid rain.

Influence of Firing Temperature on the Pozzolanic Activity of Kaolin Wastes

2012 ◽  
Vol 727-728 ◽  
pp. 675-680 ◽  
Author(s):  
Suellen Lisboa Dias ◽  
I.O. Guimarães ◽  
S.S. Figueiredo ◽  
I.M.T. Bezerra ◽  
H.C. Ferreira ◽  
...  
Keyword(s):  
Economic Growth ◽  
Compressive Strength ◽  
Thermal Treatment ◽  
Firing Temperature ◽  
Mechanical Performance ◽  
Mineral Processing ◽  
The State ◽  
Pozzolanic Activity ◽  
Mineralogical Analysis ◽  
Global Economic Growth

The volume of waste generated by mining and mineral processing industries has escalated each day because of increased demand caused by global economic growth. The kaolin processing industries are important economic segments in the state of Paraiba, but generate huge amounts of waste. An alternative for the recycling of this waste is its use in mortars. The kaolin contained in wastes after thermal treatment can reduce the consumption of cement in the production of mortars. It was evaluated the influence of firing temperatures of the residue on its pozzolanic activity. The residue was fired at temperatures of 600°C, 700°C and 800°C for 2h and subjected to mineralogical analysis. The evaluation produced the mortar with a mixture of kaolin waste burned at temperatures of 600°C, 700°C and 800°C with lime delivering true a good mechanical performance, reaching values of compressive strength greater than the legislated.

Effect of Ground Granulated Blast Furnace Slag on Compressive Strength of POFA Blended Concrete

2015 ◽  
Vol 802 ◽  
pp. 142-148
Author(s):  
M.N. Noor Azline ◽  
Farah Nora Aznieta Abd Aziz ◽  
Arafa Suleiman Juma
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Strength Development ◽  
Replacement Level ◽  
Concrete Compressive Strength ◽  
Cement Replacement ◽  
Granulated Blast Furnace Slag ◽  
Strength Tests ◽  
Furnace Slag

The article reports a laboratory experimental programme that investigated effect of ground granulated blast furnace (GGBS) on compressive strength of POFA ternary concrete. Compressive strength tests were performed at a range of cements combinations, including 100%PC, two POFA levels for binary concrete, 35% and 45%, and 15%GGBS inclusion for POFA ternary concrete. The compressive strength results were examined in comparison to PC only and equivalent POFA binary concretes for up to 28 days. Results show that the reduction in compressive strength is greater with the higher cement replacement level for all concretes particularly for POFA binary concretes. However, 15%GGBS in POFA blended concrete has a comparable compressive strength compared to PC concrete at both, 35% and 45%, cement replacement levels except for ternary concrete at 0.65 w/c. In addition, the compressive strength of ternary concrete is slightly higher compared to binary concrete for all concrete combinations. Although there is no significant noticeable influence on strength development, the presence of GGBS did not adverse the strength development of POFA blended concrete. Thus, it can be concluded that GGBS compensates the adverse effect of POFA at early strength development.

scholarly journals Beneficial Effect of Incorporation of Slag on the Hydration Heat, Mechanical Properties and Durability of Cement Containing Limestone Powder

2020 ◽  
Vol 330 ◽  
pp. 01047
Author(s):  
Toufik Boubekeur ◽  
Bensaid Boulekbache ◽  
Mohamed Salhi ◽  
Karim Ezziane ◽  
EL.Hadj Kadri
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Ordinary Portland Cement ◽  
Blended Cement ◽  
Dilution Effect ◽  
High Strength ◽  
Limestone Powder ◽  
Blended Cements ◽  
Hydration Mechanism ◽  
Durability Performance

This paper presents the experimental results of a wide research program, tending to determine the hydration mechanism, mechanical properties and the durability performance of ternary cement containing limestone powder and slag. The limestone powder increase the hydration at early ages inducing a high strength at, but it can reduce the later strength due to the dilution effect. On the other hands, Slag (S) contributes to increase the compressive strength at later ages. Hence, at medium blended cement (OPC-LP-S) with better performance could be produced. Results show at later age the Slag is very effective in producing ternary blended cements with similar on higher compressive strength than the ordinary Portland cement at 28 and 90 days. For durability, the incorporation of the slag into the cement containing limestone powder improves remarkably resistance to attack by acids and sulfates and it has been found that the durability of the cements never depends on the mechanical strength.

scholarly journals THE EFFECT OF CERAMIC WASTE AS COARSE AGGREGATE ON STRENGTH PROPERTIES OF CONCRETE

2017 ◽  
Vol 36 (3) ◽  
pp. 691-696
Author(s):  
EE Ikponmwosa ◽  
SO Ehikhuenmen
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Control Sample ◽  
Strength Properties ◽  
Waste Material ◽  
Partial Replacement ◽  
Replacement Level ◽  
Ceramic Waste ◽  
Curing Age

This paper reports the findings on an experimental investigation of the effect of partial replacement of coarse aggregate with ceramic waste on strength properties of concrete. Compressive strength tests were conducted using 150x150x150mm cube specimens, while tensile strength was investigated using 150x300mm cylinder specimens. Results of tests show that workability, density, compressive and flexural strength of concrete decreased with increase in ceramic waste content. The compressive strength at 90 days curing age for the control sample was 24.67 N/mm2. Compressive strength values at 90 days curing age for  25%, 50% and 75% replacement levels were 21.78 N/mm2, 19.85 N/mm2and 17.85 N/mm2 respectively. The decrease in density and strength was due to ceramic waste being lighter and more porous than normal coarse aggregate. Tensile strength of concrete with ceramic waste decline gradually from 8.39 N/mm2 to 6.13 N/mm2 for the control and 75% replacement samples respectively. This could be attributed to the water absorption capacity and external porcelain nature of the waste material. A production cost savings of 10.7% for 1:2:4 concrete mix was noted at 75% replacement level. This study concludes that ceramic waste could be used for both structural and non-structural works and recommends that beyond 75% replacement level, ceramic waste material should not be used in concrete structures where strength is the major consideration. http://dx.doi.org/10.4314/njt.v36i3.5

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