scholarly journals Basic Properties of Calcined Underground Ant Nest Materials and Its Influence on the Compressive Strength of Concrete

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1191 ◽  
Author(s):  
Zhou ◽  
Zhu ◽  
Qu
Keyword(s):  
Compressive Strength ◽  
Activity Index ◽  
Clay Content ◽  
Particle Morphology ◽  
Pozzolanic Activity ◽  
Ant Nest ◽  
Compressive Strength Of Concrete ◽  
Dead Plant ◽  
Nest Materials ◽  
Curing Age

Underground ant nests are typically made of soil and rubble mixed with dead plant bodies, ant secretions, and other organic substances. The clay content is high, and the natural clay materials show pozzolanic activity after calcination. In this study, the underground ant nest materials of Iridomyrmex anceps, which is a common ant in the Shanghai area, are calcined and ground, and the material properties of calcined ant nest clay powder (CANCP) are characterized from six aspects: chemical composition, particle morphology, specific gravity, specific surface area, particle size distribution and pozzolanic activity index. The pozzolanic activity of CANCP is evaluated by the strength contribution rate of pozzolanic activity, revealing that CANCP is beneficial to the strength of the mortar system from an early age. The influence of CANCP on the compressive strength of concrete is analyzed using three aspects, namely, content, curing age and calcination temperature, and it is found that the three aspects of CANCP have a strong influence on the compressive strength of concrete.

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.

Effects of 0-30% Wood Ashes as a Substitute of Cement on the Strength of Concretes

2022 ◽  
Author(s):  
Theodore Gautier Bikoko ◽  
Jean Claude Tchamba ◽  
Valentine Yato Katte ◽  
Divine Kum Deh
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Greenhouse Gases ◽  
Negative Influence ◽  
Wood Ash ◽  
The Other ◽  
Other Hand ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
Curing Age

To fight against the high cost and the increasing scarcity of cement and at the same time to reduce the CO2 greenhouse gases emission associated with the production of Portland cement, two types of wood ashes as a substitute of cement in the production of concretes were investigated. In this paper, we substituted cement by two types of species of wood ashes namely, avocado and eucalyptus ashes following the proportions ranging from 0% to 30 % on one hand, and on the other hand, we added these two types of species of wood ashes namely, avocado and eucalyptus ashes following the proportions ranging from 0% to 10 % by weight of cement in the concrete samples. After 7, 14 and 28 days of curing, compressive strength tests were conducted on these concrete samples. The findings revealed that using wood ashes as additives/admixtures or as a substitute of cement in the production/manufacturing of concrete decreased the compressive strength of concrete. Hence, it can be said that wood ash has a negative influence on the strength of concrete. At three percent (3%) and ten percent (10%) of addition, the wood ash from eucalyptus specie offers better resistance compared to the wood ash from avocado specie, whereas at five percent (5%) of addition, the wood ash from avocado specie offers better resistance compared to the wood ash from eucalyptus specie. At thirty percent (30%) of substitution, the wood ash from eucalyptus specie offers better resistance compared to the wood ash from avocado specie. The compressive strengths increase with the increase of curing age.

scholarly journals Influence of boulder machine-made sand powder on compressive strength of concrete

2021 ◽  
Vol 293 ◽  
pp. 02023
Author(s):  
Pengtao Wang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Early Stage ◽  
Cementitious Materials ◽  
Mineral Admixtures ◽  
Rock Powder ◽  
Manufactured Sand ◽  
Slag Powder ◽  
Compressive Strength Of Concrete ◽  
Curing Age

In order to recycle the boulder powder produced in the process of manufactured sand production and reduce the cost of engineering concrete, this article studied the influence of boulders powder on the compressive strength of concrete. The results show that in the early stage of concrete test, the compressive strength of rock powder concrete is slightly lower than of fly ash and mineral powder concrete. With the development of curing age, the strength of boulders powder concrete developed slower. As the increase of boulders powder content, the compressive strength of different curing age gradually decreased, and it was suggested that the content of boulders powder should be controlled within 20% of cementitious materials mass. The positive effect of boulders powder fineness on the strength of concrete is limited, so it is suggested to use unprocessed collected boulders powder in the project, which is economical and environmentally friendly. With the adjustment of water-to-binder ratio, boulders powder can be prepared with different strength grades of concrete to meet the needs of engineering; the composite of boulders powder with traditional mineral admixtures, such as fly ash, and especially granulated blast furnace slag powder, can significantly improve the strength of concrete.

Multivariate Statistical Analysis of the Wfarddc North American Fly Ash Database

1991 ◽  
Vol 245 ◽  
Author(s):  
Hans S. Pietersen ◽  
Simon P. Vriend ◽  
Gregory J. Mccarthy
Keyword(s):  
Compressive Strength ◽  
Statistical Analysis ◽  
Specific Gravity ◽  
North American ◽  
Activity Index ◽  
Pozzolanic Activity ◽  
Mineral Admixtures ◽  
Fly Ashes ◽  
Glass Chemistry ◽  
Bulk Chemistry

ABSTRACTThe database of chemical, mineralogical and physical characteristics of North American Fly ashes, assembled by the WFARDDC in North Dakota, was analyzed using multivariate statistics. Prior to the multivariate analysis, the data were rearranged in subgroups containing information on bulk-chemistry, glass chemistry, mineralogy and ASTM physical test results. These groups were analyzed individually. The multivariate technique used was Fuzzy C-Means Cluster Analysis, combined with Non-Linear Mapping. Analysis of the data-set indicates a relation between glass network former and network modifier content. The database shows that a subdivision on the basis of bulk CaO (< 11%; 11–20%; >20%) correlates well with the ASTM C618 Σ(SiO2 +Al2O3 +Fe2O3) and/or specific gravity. Mineralogical data indicate a subdivision into clusters containing varying amounts of mullite, quartz and/or ferrite spinel and a variety of Ca-containing minerals; high CaO ashes usually have high Ca-mineral contents. Of the CaO containing minerals, only portlandite contributed slightly to the compressive strength as defined by ASTM C618. Analysis of glass chemistry reveals smaller differences in absolute amounts of major oxides than would be expected on the basis of bulk chemistry alone. Surprisingly, the total glass content does not contribute significantly to 28 day compressive strength; multiple regression analysis only indicates a significant relation of particle size and specific gravity with the ASTM Pozzolanic Activity Index (portland cement). The Pozzolanic Activity Index with lime seems to be of limited importance in evaluating the performance of fly ashes as mineral admixtures in concrete. On the basis of the statistical analysis, suggestions for selection of important classifying variables are made.

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.

Effect of Curing Regime on Compressive Strength of Concrete Containing Malaysian Laterite Aggregate

2012 ◽  
Vol 626 ◽  
pp. 839-843 ◽  
Author(s):  
Norul Wahida Kamaruzaman ◽  
Khairunisa Muthusamy
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Curing Process ◽  
Normal Concrete ◽  
Strength Performance ◽  
Compressive Strength Test ◽  
Water Curing ◽  
Compressive Strength Of Concrete ◽  
Curing Regime ◽  
Curing Age

Concrete subjected to improper curing process would exhibit poor strength performance due to incomplete hydration process. This research investigate the effect of curing regime towards compressive strength of concrete containing Malaysian laterite aggregate (MLA) as partial coarse aggregate replacement. Concrete specimens produced using a range of laterite aggregate replacement from 0 to 50% were placed in different curing regime namely water curing, natural weather curing and air curing until the testing date. Specimens were subjected to compressive strength test in accordance to BS EN 12390 at 60 days. The results show strength of all specimens except the air cured samples increase as the curing age become longer. It was found that water curing is the most suitable for better performance of laterite concrete. The presence of water throughout the curing process is very much crucial for laterite concrete strength developement compared to normal concrete.

scholarly journals Effects of the incorporation of residue of masonry on the properties of cementitious mortars

2020 ◽  
Vol 19 (3) ◽  
pp. 407-421
Author(s):  
Yimmy Fernando Silva ◽  
◽  
David A. Lange ◽  
Silvio Delvasto ◽  
◽  
...  
Keyword(s):  
Compressive Strength ◽  
Activity Index ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Heat Of Hydration ◽  
Cementitious Material ◽  
Pozzolanic Activity ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Supplementary Cementitious Material

This paper presents results of an experimental study of a residue of masonry (RM), sampled from a construction and demolition waste (CDW), added as a supplementary cementitious material (SCM) to partially replace up to 50% of Portland cement in the preparation of mortars. The pozzolanic activity (fixed lime and strength activity index), setting time, heat of hydration, the (autogenous and drying) shrinkage and compressive strength tests were carried out. The results show how the RM has a positive activity because the increase of RM replacement level in the mortars generates a lower heat of hydration and autogenous and drying shrinkage. The fixed lime at 28 and 180 days, indicating that the RM exhibits in some degree pozzolanic activity and the Strength Activity Index (SAI) was 77.13% and 84.36% of the compressive strength of 100% OPC mortar at the 7 and 28 days respectively, which conformed to ASTM C311. These results indicate that RM should be considered appropriated for using as a supplementary cementitious material.

scholarly journals Compressive strength of re-vibrated concrete made from pebbles

2020 ◽  
Vol 211 ◽  
pp. 03007
Author(s):  
Auta Samuel Mahuta ◽  
Peter Emmanuel Aku
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Time Lag ◽  
Target Strength ◽  
Coarse Aggregates ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
Ongoing Development ◽  
Vibration Time ◽  
Curing Age

The search for natural and readily available structural material to meet the growing demand for ecologically friendly and smart structures is an ongoing development. In this background, an experimental study into the compressive strength of re-vibrated concrete made from pebbles as coarse aggregate is presented. Fifty-six (56) concrete cubes were cast adopting a re-vibration time lag interval of 10minutes for one hour, with a target strength of 15N/mm2. This comprised 28 cubes 100% granite and 28 cubes 100% pebbles as coarse aggregates respectively. Two curing ages were considered: 7 and 28 days. Results from the compressive strength tests of the cured specimens showed that: at successive time lag intervals there was an appreciable rise in compressive strength of concrete; observable was also a rise in the compressive strength with an increase of curing age. However, even though the maximum compressive strength of 25.64N/mm2 for 100%granite was achieved, that of 100%pebbles attained 23.33N/mm2, both at 60th minute of re-vibration time lag respectively. Hence, it can be suggested that 100% pebbles replacement for granite can be used to produce concrete with compressive strength of up to 23N/mm2 when revibrated.

New machine learning prediction models for compressive strength of concrete modified with glass cullet

2019 ◽  
Vol 36 (3) ◽  
pp. 876-898 ◽  
Author(s):  
Mohammadreza Mirzahosseini ◽  
Pengcheng Jiao ◽  
Kaveh Barri ◽  
Kyle A. Riding ◽  
Amir H. Alavi
Keyword(s):  
Machine Learning ◽  
Compressive Strength ◽  
Regression Models ◽  
Prediction Models ◽  
Curing Temperature ◽  
Sensitivity Analyses ◽  
Ground Glass ◽  
Content Type ◽  
Compressive Strength Of Concrete ◽  
Curing Age

PurposeRecycled waste glasses have been widely used in Portland cement and concrete as aggregate or supplementary cementitious material. Compressive strength is one of the most important properties of concrete containing waste glasses, providing information about the loading capacity, pozzolanic reaction and porosity of the mixture. This study aims to propose highly nonlinear models to predict the compressive strength of concrete containing finely ground glass particles.Design/methodology/approachA robust machine leaning method called genetic programming is used the build the compressive strength prediction models. The models are developed using a number of test results on 50-mm mortar cubes containing glass powder according to ASTM C109. Parametric and sensitivity analyses are conducted to evaluate the effect of the predictor variables on the compressive strength. Furthermore, a comparative study is performed to benchmark the proposed models against classical regression models.FindingsThe derived design equations accurately characterize the compressive strength of concrete with ground glass fillers and remarkably outperform the regression models. A key feature of the proposed models as compared to the previous studies is that they include the simultaneous effect of various parameters such as glass compositions, size distributions, curing age and isothermal temperatures. Parametric and sensitivity analyses indicate that compressive strength is very sensitive to the curing age, curing temperature and particle surface area.Originality/valueThis study presents accurate machine learning models for the prediction of one of the most important mechanical properties of cementitious mixtures modified by waste glass, i.e. compressive strength. In addition, it provides an insight into the effect of several parameters influencing the compressive strength. From a computing perspective, a robust machine learning technique that overcomes the shortcomings of existing soft computing methods is introduced.

scholarly journals Effect of Selected Curing Methods on Density and Compressive Strength of Concrete for Technological Self-Reliance

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Grace M Amusan ◽  
Monsuru O Popoola ◽  
Jelili O Shittu
Keyword(s):  
Compressive Strength ◽  
Construction Projects ◽  
Physical And Mechanical Properties ◽  
Sustainable Growth ◽  
Cement Ratio ◽  
Concrete Members ◽  
Self Reliance ◽  
Curing Methods ◽  
Compressive Strength Of Concrete ◽  
Curing Age

The quest to deliver construction projects within the shortest possible time handled many engineers to maneuver curing ages of concrete and this has been a major concern in construction industries due to associated failures of concrete members emanating from improper curing. This study therefore aimed at investigating the effect of different curing methods on density and compressive strength of concrete with a view to enhancing technological self-reliance of the nation. Concrete cube specimens (150 mm × 150 mm × 150 mm) were cast using mix ratio 1:2:4 with 0.5 water-cement ratio. The concrete specimens were cured for 28 days using open air, ponding, sprinkling and dry covering curing methods. The compressive strength and density were evaluated. The data were validated. The results showed that the compressive strength increases with increasing curing age. The respective compressive strength values obtained for ponding, sprinkling, dry covering and open air curing methods were 22.04, 20.48, 17.28 and 16.02 respectively. The curing methods have compressive strengths in the order Ponding < sprinkling < dry covering < open air. The results of the curing methods on density were also noticed to be directly proportional to strength. Appropriate curing methods of concrete had greater impact in influencing physical and mechanical properties of concrete.Keywords: Concrete, Curing methods, Strength, Sustainable growth

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