Rheological and Physical Properties of Magesium Oxide and Silica Fume-Modified Cement Mortars Cured at High Temperature

1982 ◽  
Vol 15 ◽  
Author(s):  
Zenbe-e Nakagawa ◽  
Elizabeth L. White ◽  
Della M. Roy
Keyword(s):  
Physical Properties ◽  
Silica Fume ◽  
Intrinsic Permeability ◽  
Expansive Agent ◽  
Granulated Blast Furnace Slag ◽  
Cement Mortars ◽  
Sealing Materials ◽  
Furnace Slag ◽  
By Products ◽  
Very High

ABSTRACTPhysical properties and placement characteristics of cementitious mortars have been studied for their potential as repository sealing materials. They contained various expansive agents and industrial by-products, and were investigated at curing temperatures up to 250° C, the upper limit of an emplacement site or generally of relevance in accelerated reaction studies. An expansive agent, magnesium oxide, and two industrial by-products, silica fume and granulated blast furnace slag have been used at different percentages in the mixtures. Excellent general performance, including very high strengths up to 240 MPa combined with very low intrinsic permeability <10−8 Darcy (μm2) were generated at 175°C on material having a viscosity of 5000 cP (mPa·s) at 38° C. One 1700 cP(mPa·s) material treated at 250°C had compressive strength >180 MPa and also <10−8 Darcy (μm2) permeability. MgO was found to accelerate formation of tobermorite and generally cause expansion; at 250° C expansion was also related to xonotlite formation.

A Review on the Effects of Various Supplementary Cementitious Materials on Physical Properties of Hardened Concrete

2014 ◽  
Vol 905 ◽  
pp. 287-291
Author(s):  
Salim Barbhuiya ◽  
Hamid Nikraz
Keyword(s):  
Physical Properties ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Hardened Concrete ◽  
Granulated Blast Furnace Slag ◽  
Current Trends ◽  
Fuel Ash ◽  
Treatment And Disposal ◽  
Furnace Slag ◽  
By Products

The global development and current trends in social attitude are resulting in an increase in the amount of waste generated by society, the treatment and disposal of which are becoming a serious problem. Therefore, waste management is one of the most important aspects in ensuring sustainable development in todays world. Some of the industrial by-products, such as pulverised-fuel ash (PFA), ground granulated blast-furnace slag (GGBS) and microsilica (MS) can be used in concrete to improve its properties. In this paper the influence of various by-products on the physical properties of concrete is reviewed.

Calorimetric determination of the effect of additives on cement hydration process

2013 ◽  
Vol 67 (2) ◽  
Author(s):  
Pavel Šiler ◽  
Josef Krátký ◽  
Iva Kolářová ◽  
Jaromír Havlica ◽  
Jiří Brandštetr
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Maximum Temperature ◽  
Granulated Blast Furnace Slag ◽  
Mineral Components ◽  
Maximum Temperatures ◽  
The Impact ◽  
Furnace Slag ◽  
Calorimetric Determination

AbstractPossibilities of a multicell isoperibolic-semiadiabatic calorimeter application for the measurement of hydration heat and maximum temperature reached in mixtures of various compositions during their setting and early stages of hardening are presented. Measurements were aimed to determine the impact of selected components’ content on the course of ordinary Portland cement (OPC) hydration. The following components were selected for the determination of the hydration behaviour in mixtures: very finely ground granulated blast furnace slag (GBFS), silica fume (microsilica, SF), finely ground quartz sand (FGQ), and calcined bauxite (CB). A commercial polycarboxylate type superplasticizer was also added to the selected mixtures. All maximum temperatures measured for selected mineral components were lower than that reached for cement. The maximum temperature increased with the decreasing amount of components in the mixture for all components except for silica fume. For all components, except for CB, the values of total released heat were higher than those for pure Portland cement samples.

scholarly journals The efficiency of plasticizing surfactants in alkali-activated cement mortars and concretes

2018 ◽  
Vol 230 ◽  
pp. 03016 ◽  
Author(s):  
Raisa Runova ◽  
Volodymyr Gots ◽  
Igor Rudenko ◽  
Oleksandr Konstantynovskyi ◽  
Oles’ Lastivka
Keyword(s):  
Compressive Strength ◽  
Blast Furnace Slag ◽  
Chemical Nature ◽  
Granulated Blast Furnace Slag ◽  
Cement Mortars ◽  
Alkaline Component ◽  
Property Modification ◽  
Furnace Slag ◽  
Alkali Activated ◽  
Strength In Bending

Functionality of mortar and concrete mixes is regulated by surfactants, which act as plasticizers. The molecular structure of these admixtures can be changed during hydration of alkali-activated cements (AAC). The objective was to determine the chemical nature of plasticizers effective for property modification of mortars and concretes based on AACs with changing content of granulated blast furnace slag from 0 to 100 %. The admixtures without ester links become more effective than polyesters when content of alkaline component increase. The admixtures effective in high alkaline medium were used in dry mixes for anchoring (consistency of mortar 150 mm by Vicat cone; 1 d tensile strength in bending / compressive strength of mortar 6.6 /30.6 MPa) and in ready-mixed concretes (consistency class changed from S1 to S3, S4 with consistency safety during 60 min; 3 d compressive strength of modified concrete was not less than the reference one without admixtures).

Assessment of post-heat behavior of cement mortar incorporating silica fume and granulated blast-furnace slag

2020 ◽  
Vol 11 (2) ◽  
pp. 221-246
Author(s):  
Ghasem Pachideh ◽  
Majid Gholhaki
Keyword(s):  
Tensile Strength ◽  
Flexural Strength ◽  
Blast Furnace Slag ◽  
Strength Test ◽  
Content Type ◽  
Granulated Blast Furnace Slag ◽  
Cement Mortars ◽  
Strength Tests ◽  
Pozzolanic Materials ◽  
Furnace Slag

Purpose With respect to the studies conducted so far and lack of researches on the post-heat behavior of cement mortars containing pozzolanic materials, the purpose of this paper is to investigate the post-heat mechanical characteristics (i.e. compressive, tensile and flexural strength) of cement mortars containing granulated blast-furnace slag (GBFS) and silica fume (SF). In doing so, selected temperatures include 25, 100, 250, 500, 700 and 9000c. Last, the X-ray diffraction test was conducted to study the microstructure of mixtures and subsequently, the results were presented as power-one mathematical relations. Design/methodology/approach Totally, 378 specimens were built to conduct flexural, compressive and tensile strength tests. Accordingly, these specimens include cubic and prismatic specimens with dimensions of 5 × 5 × 5 cm and 16 × 4 × 4 cm, respectively, to conduct compressive and flexural strength tests together with briquette specimen used for tensile strength test in which cement was replaced by 7, 14 and 21 per cent of SF and GBFS. To study the effect of temperature, the specimens were heated. In this respect, they were heated with a rate of 5°C/min and exposed to temperatures of 25 (ordinary temperature), 100, 250, 500, 700 and 900°C. Findings On the basis of the results, the most profound effect of using GBFS and SF, respectively, takes place in low (up to 250°C) and high (500°C and greater degrees) temperatures. Quantitatively, the compressive, tensile and flexural strengths were enhanced by 73 and 180 per cent, 45 and 100 per cent, 106 and 112 per cent, respectively, in low and high temperatures. In addition, as the temperature elevates, the particles of specimens containing SF and GBFS shrink less in size compared to the reference specimen. Originality/value The specimens were cured according to ASTMC192 after 28 days placement in the water basin. First, in compliance with what has been specified by the mix design, the mortar, including pozzolanic materials and superplasticizer, was prepared and then, the sampling procedure was conducted on cubic specimens with dimension of 5 × 5 × 5 mm for compressive strength test, prismatic specimens with dimensions of 16 × 4 × 4 mm for flexural strength test and last, briquette specimens were provided to conduct tensile strength tests (for each temperature and every test, three specimens were built).

A Strength Model for Concretes Containing Fly Ash, Blast-Furnace Slag and Silica Fume

1985 ◽  
Vol 65 ◽  
Author(s):  
Edwin R. Dunstan
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Concrete Strength ◽  
Pozzolanic Reaction ◽  
Strength Data ◽  
Production Mechanisms ◽  
Furnace Slag ◽  
By Products

ABSTRACTThis paper describes preliminary a model for the strength of concretes containing industrial by-products such as fly ash, blast-furnace slag, and silica fume. A formula that describes the various strength production mechanisms of these by-products is developed. These materials produce strength by pozzolanic reaction, by latently hydraulic reactions and by self-cementing reactions similar to Portland cement. A method of separating the effect of each mechanism is proposed. A parameter for each of these strength producing mechanisms can be determined from concrete strength data.

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