The Influence of Aggregates on the Properties of Concrete

2014 ◽  
Vol 1000 ◽  
pp. 277-280 ◽  
Author(s):  
Pavel Šiler ◽  
Ondřej Bezděk ◽  
Iva Kolářová ◽  
Eva Bartoníčková ◽  
Tomáš Opravil ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Particle Size Analysis ◽  
Hydration Process ◽  
Silica Sand ◽  
Size Analysis ◽  
Isoperibolic Calorimetry

This work is focused on the influence of aggregates on the mechanical properties of concrete and hydration process. The flexural strength and compressive strength were observed after 1, 7 and 28 days of curing. The process of hydration was monitored using isoperibolic calorimetry. Laser particle size analysis of aggregates was also performed. The following materials were used: Portland cement CEM I 42,5 R-Sc, finely ground silica sand, calcinated bauxite, fine, medium and rough testing sand (defined in ČSN EN 196-1).

scholarly journals HYDRATION PROCESS AND MECHANICAL PROPERTIES OF CEMENT PASTE WITH RECYCLED CONCRETE POWDER AND SILICA SAND POWDER

2017 ◽  
Vol 13 ◽  
pp. 125
Author(s):  
Jaroslav Topič ◽  
Zdeněk Prošek
Keyword(s):  
Mechanical Properties ◽  
Cement Paste ◽  
Particle Size Analysis ◽  
Recycled Concrete ◽  
Hydration Process ◽  
Silica Sand ◽  
Size Analysis ◽  
Calorimetric Measurement ◽  
Partial Cement Replacement ◽  
Density Dynamic

Recycled concrete powder (RCP) mostly consisting of cement paste could be reused as partial cement replacement. The aim of this paper is to compare hydration and mechanical properties of RCP and two types of silica sand powder (SSP). Comparison of those materials combined with cement can highlight the binder properties of recycled concrete powder. Using of two types of SSP also show an influence of their fines on hydration process and mechanical properties. Particle size analysis and calorimetric measurement were carried out and mechanical properties such as bulk density, dynamic Young’s modulus and compression strength were examine. Calorimetric measurement proves the presence of exposed non-hydrated particles in RCP that can react again. However lower density of old cement paste in RCP overweight the mentioned potential of RCP and mechanical properties are decreasing compared with reference cement paste and cement paste SSP.

Pressure assisted sintering of Al2O3–Y2O3 glass microspheres: sintering conditions, grain size, and mechanical properties of sintered ceramics

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Anna Prnová ◽  
Jana Valúchová ◽  
Monika Michálková ◽  
Beáta Pecušová ◽  
Milan Parchovianský ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Hot Pressing ◽  
Pechini Method ◽  
Sol Gel ◽  
Applied Pressure ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Glass Microspheres ◽  
Amorphous Powders

Abstract Glass microspheres with yttria-alumina eutectic composition (76.8 mol % Al2O3 and 23.2 mol % Y2O3) were prepared by sol-gel Pechini method and flame synthesis with or without subsequent milling. Prepared amorphous powders were studied by X-ray powder diffraction (XRD), particle size analysis (PSA), scanning electron microscopy (SEM) and differential thermal analysis (DTA). Hot pressing (HP), rapid hot pressing (RHP) and spark plasma sintering (SPS) were used to sinter amorphous precursor powders at 1600 °C without holding time (0 min). The preparation process including milling step resulted in amorphous powders with narrower particle size distribution and smaller particle size. All applied pressure assisted sintering techniques resulted in dense bulk samples with fine grained microstructure consisting of irregular α-Al2O3 and Y3Al5O12 (YAG) grains. Milling was beneficial in terms of final microstructure refinement and mechanical properties of sintered materials. A material with the Vickers hardness of HV = (17.1 ± 0.3) GPa and indentation fracture resistance of (4.2 ± 0.2) MPa.m1/2 was prepared from the powder milled for 12 h.

scholarly journals Recent Advances in Magnesia Blended Cement Studies for Geotechnical Well Construction—A Review

2021 ◽  
Vol 8 ◽  
Author(s):  
Weiqing Chen ◽  
Salaheldin Elkatatny ◽  
Mobeen Murtaza ◽  
Ahmed Abdulhamid Mahmoud
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Portland Cement ◽  
Supplementary Cementitious Materials ◽  
Research Progress ◽  
Size Analysis ◽  
Strength Testing ◽  
Cement Material ◽  
The Impact ◽  
Caustic Magnesia

The current paper presents a literature review on the studies of incorporation of magnesia (magnesium oxide) into Portland cement material from the geotechnical well construction perspective. Starting with a comparison of application conditions between civil construction and geotechnical well cementing, this work reviewed the Portland cement categorizations, magnesia manufacturing routes at first. Then, the physical-chemical-mechanical properties were investigated which includes the reactivity of magnesia, expansion influence from its hydration, and carbonation/dehydroxylation of magnesia blended Portland cement. The development of cement material hydration modeling methods is also summarized. Moreover, the experimental characterization methods have also been elucidated including composition determination, particle size analysis, volumetric variation measurement, compressive strength testing, shear-bond strength testing, transition state analysis, etc. Meanwhile, the results and conclusions were extracted from the literature. Through this route, a comprehensive understanding of the scientific research progress on magnesia blended Portland cement development for geotechnical well construction is derived. Additionally, it is concluded that incorporating magnesia into Portland cement can provide benefits for this material utilization in geotechnical well constructions provided the reasonable tuning among the characteristics of magnesia, the downhole surrounding conditions, and the formulation of the cement slurry. Satisfying these pre-conditions, the effective expansion not only mitigates the micro-annulus issues but also increases the shear bonding strength at the cementing interfaces. Moreover, the caustic magnesia introduction into Portland cement has the potential advantage on carbon dioxide geological sequestration well integrity compared with the Portland cement sheath without it because of the denser in-situ porous matrix evolvement and more stable carbon fixation features of magnesium carbonate. However, since the impact of magnesia on Portland cement strongly depended on its properties (calcination conditions, particle size, reactivity) and the aging conditions (downhole temperature, pressure, contacting medium), it should be noted that some extended research is worth conducting in the future such as the synchronized hydration between magnesia and Portland cement, the dosage limit of caustic magnesia in Portland cement in terms of CO2 sequestration and the corresponding mechanical properties analysis, and the hybrid method (caustic magnesia, Portland cement, and other supplementary cementitious materials) targeting the co-existence of the geothermal environment and the corrosive medium scenario.

Preparation and Characterization of Bone Cements Incorporated with Montmorillonite

2007 ◽  
Vol 342-343 ◽  
pp. 753-756
Author(s):  
Sun Yeon Lee ◽  
Sung Soo Kim
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Average Particle Size ◽  
Gel Permeation Chromatography ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Average Particle ◽  
Bone Cements ◽  
Liquid Component ◽  
Powder Component

Bone cements incorporated with montmorillonite (MMT) were prepared in an attempt to improve their mechanical properties. The cements were characterized using particle size analysis, gel permeation chromatography, viscosity measurements, X-ray diffraction, transmission electron microscopy, and mechanical properties. The average particle size and molecular weight of the PMMA powders used were 47 μm and 100,000 g/mol, respectively. The incorporation of MMT led to an increase in viscosity of the bone cement but did not severely affect its setting temperature or the amount of residual monomer. Regardless of the MMT mixing methods used, in this case MMT being mixing in liquid and powder components, sodium MMT (SMMT) was not well dispersed in the bone cements, which was believed to be due to its hydrophilicity. Organophilic MMT (OMMT) was better dispersed in the liquid component than in the powder component. The tensile and compressive strengths of the bone cements with 0.5 wt% OMMT mixed in the liquid component were 35.9 and 119.6 MPa, respectively, which were considerably higher than those of the bone cements with 0.5 wt% OMMT mixed in the powder component (27.9 and 100.5 MPa, respectively).

Study on Mechanical Properties of Soda Residue / Fly Ash Composite Cementitious Material

2011 ◽  
Vol 194-196 ◽  
pp. 1026-1029
Author(s):  
Bao Jia Li ◽  
Guo Zhong Li
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Portland Cement ◽  
Cementitious Material

The composite cementitious material was prepared with soda residue and fly ash. The mechanical properties were improved by mixing calcined lime and Portland cement, and the mechanism of admixture was researched. The results showed that the 28d flexural strength reached 3.59MPa and the 28d compressive strength reached 9.71MPa., when the proportion of soda residue and fly ash was 40:60 with 9% Portland cement and 7% calcined lime added.

scholarly journals Soil characterization for adobe mixtures containing Portland cement as stabilizer

2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Lucas Miranda Araújo Santos ◽  
José Anselmo da Silva Neto ◽  
Aline Figueirêdo Nóbrega de Azerêdo
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Distribution Curve ◽  
Cement Content ◽  
Clay Content ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Physical And Chemical ◽  
Method Analysis

ABSTRACT One of the most economical ways to build with soil is to use adobe technique. There are several types of soils and most of them are not suitable for using to construct buildings. Physical and chemical characteristics of the soils will influence on its performance to use for buildings. This work aims to characterize physically, chemically and mineralogically two soil samples and study the dosage of mixtures for adobe using Portland cement as stabilizer. It was studied three different Portland cement content (6%, 9% and 12%) in the soil. The results showed that compressive strength of up to 5 MPa at 28 days for both type of soils studied with 12% of Portland cement. In addition, a comparison between two methods used for the particle size analysis of the soils. It was observed that the results differed in each method analysis. Overall this work has shown that to use these soils for adobe bricks, 9% of Portland cement is enough to reach the minimum compressive strength required by standard. Furthermore, this research brings results about the determination of the clay content of the soil, indicating that the traditional method to determine the size distribution curve by sieving and sedimentation may not be the most suitable to check this clay content.

scholarly journals Effect of the Content of Micro-Active Copper Tailing on the Strength and Pore Structure of Cementitious Materials

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1861 ◽  
Author(s):  
Liming Zhang ◽  
Songbai Liu ◽  
Dongsheng Song
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Pore Structure ◽  
Cement Hydration ◽  
Early Stage ◽  
Cementitious Materials ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Strength Increase ◽  
Curing Age

This study investigates the effect of micr-oaggregate filling with copper tailing on the pore structure of cement paste containing copper tailing (CPCT). The particle size of the CPCT and the pore structure of CPCT were analyzed by laser particle size analysis and mercury instruction porosimetry (MIP). Results showed that at the early stage of curing time, with increasing copper tailing content, the compressive strength of cement mortar with copper tailing (CMCT) was lower, and the porosity and pore diameter of CPCT were higher and greater; with the extension of curing age, when the content of copper tailing was less than 30%, the compressive strength of CMCT and the porosity of CPCT changed slightly with the increase of the content of copper tailing. However, the maximum hole diameter of CPCT decreased gradually (a curing age between 7 d and 365 d under standard conditions). Scanning electron microscopy analysis showed that at the early stage of cement hydration in the CPCT, the copper tailing did not fill the pores in CPCT well, while in the later stage of cement hydration, the microaggregates of copper tailing filled the pores well and closely combined with the surrounding hydration products. In the later stage of cement hydration, the microaggregate filling of copper tailing was primarily responsible for the strength increase of the CMCT.

Study of Mechanical Properties and Physical Properties of Rubberized Portland Cement Concrete

2012 ◽  
Vol 512-515 ◽  
pp. 2812-2816
Author(s):  
Wei Li ◽  
Xiao Chu Wang ◽  
Hong Tao Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Silica Fume ◽  
Rubber Particle ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Cleavage Strength ◽  
Research Situation

This test summers up the research situation of rubber powder modifier. According to tests of density, flexural strength, compressive strength and cleavage strength, this test analyzes the basic mechanical properties and the variation of rubberized portland cement concrete which is mixing the silica fume modifier. The results show that the flexural strength, compressive strength and cleavage strength of concrete may increase when silica fume concrete admixture modifiers is mixed in cement concrete. The workability, density, flexural strength, compressive strength, ratio of compressive strength and cleavage strength of rubberized portland cement concrete gradually reduced with the increase in dosage of rubber. The rubber particles mixed with concrete which can when the rubber particle size is not more than 30% of the dosage of coarse aggregate, the fine pavement of rubberized portland cement concrete can be got.

The Carbon Black Sonofication Effects on Vulcanisate Properties of Natural Rubber

2012 ◽  
Vol 626 ◽  
pp. 114-120 ◽  
Author(s):  
Mahendra Anggaravidya ◽  
Sudirman Sudirman ◽  
Bambang Soegijono ◽  
Emil Budianto ◽  
Martin Djamin
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Carbon Black ◽  
Natural Rubber ◽  
Carbon Black Particle ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Black Particle ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

The mechanical properties of natural rubber can be enhanced by the addition of carbon black. The mechanical properties change is highly affected by particle size and carbon black structure used. A modification of N660 carbon black was conducted in the research by sonoficating the carbon black for 3 and 5 hours (N600-M3; M5). The results of adding modified carbon black were characterised by Particle Size Analysis (PSA), Scanning Electron Microscopes - Energy Dispersive Spectrometry (SEM-EDS) and Thermogravimetric Analysis (TGA). The addition of modified carbon black shows bound rubber, thermal properties, and mechanical properties such as tensile strength, elongation at break and modulus 300% on the vulcanisate produced were increased from the vulcanisate that had been filled with N660 natural (N660-N). Keywords: natural rubber, carbon black, particle size, sonofication, characterisation

scholarly journals Particle Size Effect of Oyster Shell on Mortar: Experimental Investigation and Modeling

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6813
Author(s):  
Yingdi Liao ◽  
Hongyi Shi ◽  
Shimin Zhang ◽  
Bo Da ◽  
Da Chen
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Particle Sizes ◽  
River Sand ◽  
Standard Requirement ◽  
Slump Flow ◽  
Curing Age

In order to solve the problem of lack of natural river sand, crushed waste oyster shells (WOS) were used to replace river sand. By replacing 20% river sand, WOS mortar with different particle sizes of WOS were made for the experiment. Through experimental observation, the initial slump and slump flow loss rate were studied. The effects of different particle sizes and curing times on the compressive strength, flexural strength, static elastic modulus, and dry shrinkage of WOS mortar were analyzed. The relationship formulas between the compressive strength, flexural strength, particle size, and curing age were proposed. The results showed that the setting time and slump flow decreased with a decrease in the particle size of WOS. It was also found that the mortar with fine crushed WOS had high compressive strength, flexural strength, and static elastic modulus at both early and long-term curing age. A formula was proposed to describe the development of the compressive strength with the particle size of WOS and curing time, and the relations among these mechanical properties were discussed. Furthermore, drying shrinkage increased when WOS was used and could not satisfy the standard requirement of 0.075%. In contrast, the addition of fine WOS and double-dose sulfonated naphthalene-formaldehyde superplasticizer (SNF SP) reduced the shrinkage rate of the mortar by 8.35% and provided better workability and mechanical properties for mortar.

Sign in / Sign up

Export Citation Format

Share Document