scholarly journals Performance Evaluation of Ordinary Portland Cement with GGBFS and Portland Slag Cement at Same GGBFS Replacement Level in Concrete

2018 ◽  
Vol 203 ◽  
pp. 06004
Author(s):  
Ramesh Babu Chokkalingam ◽  
Manikandan Rajakannu
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Concrete Structures ◽  
Blended Cement ◽  
Mineral Admixtures ◽  
Slag Cement ◽  
Control Practice ◽  
Cement Manufacturing ◽  
Portland Slag Cement ◽  
Durability Of Concrete

Literature review indicates that the usage of mineral admixtures (Fly ash, Ground Granulated Blast Furnace Slag, Silica Fume and Rice Husk ash) significantly improves the durability of concrete structures. Though it is reported as best alternative materials for improving durability of concrete structures, it was not very well received in government projects in India till 1990. However, for the past two decades, the usage of mineral admixtures directly or in the form of blended cement in concrete have significantly increased. Major concern of using mineral admixtures which was persisting among majority of the Ordinary Portland Cement (OPC) users are (i) delayed setting and strength gain, affecting the rate of construction, (ii) inconsistent in quality of mineral admixtures, mostly happened in site blending (iii) no established results pertains to Indian condition. In India, mostly the usage of mineral admixtures in concrete are used as a replacement for OPC, specifically in Ready Mix Concrete and site batching plant. However, few literature have reported that usage of mineral admixtures in the form of blended cement which is made at cement manufacturing plant by either intergrinding or blending will exhibits better concrete properties due to consistent quality and better quality control practice followed. Hence, the authors have undertaken this study to investigate the performance of mineral admixtures (only GGBFS) as direct replacement materials and as blended cement in concrete. In order to understand in detail, both as replacement of OPC and in the form of PSC, was undertaken on various cement content in concrete, i.e., 300, 320, 340, 360, 380 kg/m3. Results of compressive strength at various age of curing indicates that usage of GGBFS in the form of Portland Slag Cement (PSC) shows better performance than as a replacement of OPC in concrete.

Influence of Plasticizer on Properties of Blended Cement Concrete

2015 ◽  
Vol 824 ◽  
pp. 61-64
Author(s):  
Kirill Polozhiy ◽  
Jamal Akhter Siddique ◽  
Pavel Reiterman
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Blended Cement ◽  
Cement Concrete ◽  
Slag Cement ◽  
Red Clay ◽  
Clay Ceramics ◽  
Portland Slag Cement ◽  
Partial Activity

In this article Portland-slag cement was step by step replaced with pozzolana (fine red-clay ceramics) in concrete. This is first step of research that is why the only measured characteristics were consistency of mixtures and compressive strength. There were designed four mixtures with increasing replacement of Portland cement by 10 % each (CR, C1, C2, C3) where complete activity of pozzolana was assumed. Mixtures C4, C5 and C6 were designed with respect to presumed just partial activity of the used pozzolana (set as 40 %). The water/cement coefficient was decided to be taken according to the consistence of the mortar.

scholarly journals Artificial Neural Network Estimation of the Effect of Varying Curing Conditions and Cement Type on Hardened Concrete Properties

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Gökhan Kaplan ◽  
Hasbi Yaprak ◽  
Selçuk Memiş ◽  
Abdoslam Alnkaa
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Hardened Concrete ◽  
Slag Cement ◽  
Curing Conditions ◽  
Concrete Properties ◽  
Concrete Production ◽  
Artificial Neural

The use of mineral admixtures and industrial waste as a replacement for Portland cement is recognized widely for its energy efficiency along with reduced CO2 emissions. The use of materials such as fly ash, blast-furnace slag or limestone powder in concrete production makes this process a sustainable one. This study explored a number of hardened concrete properties, such as compressive strength, ultrasonic pulse velocity, dynamic elasticity modulus, water absorption and depth of penetration under varying curing conditions having produced concrete samples using Portland cement (PC), slag cement (SC) and limestone cement (LC). The samples were produced at 0.63 and 0.70 w/c (water/cement) ratios. Hardened concrete samples were then cured under three conditions, namely standard (W), open air (A) and sealed plastic bag (B). Although it was found that the early-age strength of slag cement was lower, it was improved significantly on 90th day. In terms of the effect of curing conditions on compressive strength, cure W offered the highest compressive strength, as expected, while cure A offered slightly lower compressive strength levels. An increase in the w/c ratio was found to have a negative impact on pozzolanic reactions, which resulted in poor hardened concrete properties. Furthermore, carbonation effect was found to have positive effects on some of the concrete properties, and it was observed to have improved the depth of water penetration. Moreover, it was possible to estimate the compressive strength with high precision using artificial neural networks (ANN). The values of the slopes of the regression lines for training, validating and testing datasets were 0.9881, 0.9885 and 0.9776, respectively. This indicates the high accuracy of the developed model as well as a good correlation between the predicted compressive strength values and the experimental (measured) ones.

Experimental Study on Compatibility between Alkali-Free Liquid Concrete Accelerators and Cement

2013 ◽  
Vol 438-439 ◽  
pp. 102-107 ◽  
Author(s):  
Wen Kang Guo ◽  
Li Wang ◽  
Shu Yin Wang ◽  
Dao Yin Lan ◽  
Sheng Ping Li
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Strength Ratio ◽  
Setting Times ◽  
Gypsum Content ◽  
Durability Of Concrete

This paper selected two kinds of alkali-free liquid concrete accelerators and tested their compatibility with ordinary Portland cement, Portland cement and moderate heat Portland cement by measuring the setting times, compressive strength and compressive strength ratio of samples. The results showed that the compatibility is good between alkali-free accelerators and two types of cement: ordinary Portland cement and moderate heat Portland cement. However, the compatibility of two accelerators and Portland cement are quite different, the compatibility of AFA-2 accelerator is excellent, but AFA-1 accelerator is very poor. The setting times of alkali-free accelerators is mainly influenced by the mixing materials content, gypsum content, C3A and C3S content. In order to ensure the mechanical properties and durability of concrete, the setting times of new concrete accelerator is not the shorter the better, the appropriate initial and final setting times are 1min30s~5min and 4min~ 12min respectively.

BEHAVIOR OF M 50 GRADE SELF-COMPACTING CONCRETE DEVELOPED USING PORTLAND SLAG CEMENT AND METAKAOLIN

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Sravya Nalla ◽  
Janardhana Maganti ◽  
Dinakar Pasla
Keyword(s):  
Compressive Strength ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Test Results ◽  
Slag Cement ◽  
Self Compacting Concrete ◽  
Destructive Testing ◽  
Compressive Strength Test ◽  
Portland Slag Cement ◽  
Strength And Durability

Self-compacting concrete (SCC) is a revolutionary development in concrete construction. The addition of mineral admixtures like metakaolin, which is a highly reactive pozzolana to the SCC mixes, gives it superior strength and durability. The present work is an effort to study the behavior of M50 grade SCC by partial replacement of Portland Slag Cement (PSC) with metakaolin. Its strength and durability aspects are comparable with a controlled concrete (without replacement of cement). In the present work, a new mix design methodology based on the efficiency of metakaolin is adopted. The optimum percentage replacement of cement with metakaolin is obtained based on compressive strength test results. The influence of metakaolin on the workability, compressive strength, splitting tensile strength and flexural strength of SCC and its behavior when subjected to elevated temperature was investigated through evaluation against controlled concrete and non-destructive testing. From the test results, it was observed that incorporation of metakaolin at an optimum dosage satisfied all the fresh properties of SCC and improved both the strength and durability performance of SCC compared to controlled concrete.

scholarly journals Diffusion Decay Coefficient for Chloride Ions of Concrete Containing Mineral Admixtures

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Jae-Im Park ◽  
Kwang-Myong Lee ◽  
Soon-Oh Kwon ◽  
Su-Ho Bae ◽  
Sang-Hwa Jung ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Concrete Structures ◽  
Blended Cement ◽  
Chloride Ions ◽  
Mineral Admixture ◽  
Curing Temperature ◽  
Mineral Admixtures ◽  
Exposure Condition ◽  
Diffusion Decay ◽  
Decay Coefficient

The diffusion coefficient for chloride ions and the diffusion decay coefficient for chloride ions are essential variables for a service life evaluation of concrete structures. They are influenced by water-binder ratio, exposure condition, curing temperature, cement type, and the type and use of mineral admixture. Mineral admixtures such as ground granulated blast furnace slag, fly ash, and silica fume have been increasingly used to improve resistance against chloride ions penetration in concrete structures built in an offshore environment. However, there is not enough measured data to identify the statistical properties of diffusion decay coefficient for chloride ions in concrete using mineral admixtures. This paper is aimed at evaluating the diffusion decay coefficient for chloride ions of concrete using ordinary Portland cement or blended cement. NT BUILD 492 method, an electrophoresis experiment, was used to measure the diffusion coefficient for chloride ions with ages. It was revealed from the test results that the diffusion decay coefficient for chloride ions was significantly influenced by W/B and the replacement ratio of mineral admixtures.

Hybrid Cements with Non Silicate Activators

2017 ◽  
Vol 259 ◽  
pp. 30-34 ◽  
Author(s):  
Vlastimil Bílek ◽  
Filip Khestl ◽  
Pavel Mec
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Mineral Admixtures ◽  
Alkali Activation ◽  
Granulated Blast Furnace Slag ◽  
Mineral Additions ◽  
New Type ◽  
Furnace Slag

Hybrid cements represent a relatively new type of binders which combines some of the advantages of Ordinary Portland Cement and an application of mineral admixtures and alkali activation. Hybrid cements form then blends containing a low portion of OPC and a high proportion of mineral additions (such as blast furnace flag, fly ash, metakaoline, ...). This paper discusses the properties of mortars based on carbonate based activators. Mixtures composed from Ordinary Portland Cement, ground granulated blast furnace slag, fly ash and mechanically pre-activated fly ash were optimised with the target to achieve sufficient compressive strength. The influence of ratios between powder compounds, the dosage of activator and water to binder ratios are presented.

Improving the Efficiency of Slag Portland Cement by Reducing Shrinkage Deformations

2020 ◽  
Vol 992 ◽  
pp. 104-110
Author(s):  
Svetlana V. Samchenko ◽  
D.A. Zorin
Keyword(s):  
Portland Cement ◽  
Compression Strength ◽  
Cement Hydration ◽  
Early Stage ◽  
Cement Clinker ◽  
Cement Stone ◽  
Slag Cement ◽  
Portland Cement Clinker ◽  
Granulated Slag ◽  
Portland Slag Cement

The influence of the artificial additive introduced at the joint grinding of granulated slag, Portland cement clinker and gypsum on the Portland slag cement hydration, its compression strength at an early stage and shrinkage deformation is investigated. It was found that in the presence of sulfoferrite clinker there is an amorphization of cement stone structure with formation of stone with high density and strength in early setting. The open porosity of the hardened paste is reduced by 13 – 15 % in comparison with plain Portland slag cement. The samples strength increases by 1.55 - 1.78 times at grade stage, by 15.5 - 19.4 % in bending and by 6.4 - 11.2 % in compression.

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