scholarly journals Salt-Frost Scaling of Concrete with Slag and Fly Ash - Influence of Carbonation and Prolonged Conditioning on Test Results

2020 ◽  
Vol 63 (2) ◽  
pp. 89-108
Author(s):  
Elisabeth Helsing ◽  
Peter Utgenannt
Keyword(s):  
Fly Ash ◽  
Frost Resistance ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Supplementary Cementitious Material ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio ◽  
Swedish Experience ◽  
Entrained Air ◽  
Water To Binder Ratio

AbstractAccording to Swedish experience the slab method in CEN/TS 12390-9 is successful in predicting the salt-frost resistance of Portland cement concrete. However, doubts have been raised whether the same can be said when used on concrete with supplementary cementitious material, e.g. fly ash or ground granulated blast furnace slag (GGBS). Test results from concrete mixes with up to 35 % fly ash 65 % GGBS, with two different Portland cements and a water-to-binder ratio of 0.45 are presented in this paper. The tests were carried out with the standard method and with five modifications concerning the pre-conditioning of the specimens before freeze-thaw cycling. The age of the specimens at sawing was increased, the time in 65 % RH was prolonged and exposure to 1 % CO2-environment was used. The results show that for air-entrained concrete with fly ash or GGBS both prolonging the exposure to 65 % RH and exposure to CO2 diminishes the salt-frost resistance. The influence increases with increasing amount of fly ash or GGBS. However, the type of cement also has a certain influence. The influence of exposure to CO2 on the salt-frost resistance of concrete without entrained air was totally different from the influence on concrete with entrained air.

Influence of Fly Ash on Abrasion Resistance of Concretes with their Additions

2013 ◽  
Vol 592-593 ◽  
pp. 651-654
Author(s):  
Aneta Nowak-Michta
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Abrasion Resistance ◽  
Test Results ◽  
Reference Test ◽  
Binder Ratio ◽  
Alternative Test ◽  
Water To Binder Ratio ◽  
Standard Tests ◽  
Class F

The influence of fly ash quality and quantity on abrasion resistance of hardened concretes with siliceous fly ash addition is analysed in the paper. Abrasion resistance was measured in two standard tests according to EN 1338: 2005: reference test of the Wide Wheel and alternative test of the Bohme. Cement was replaced with 20, 35, and 50% of Class F siliceous fly ash in three categories of losses of ignition A, B and C by mass. The water to binder ratio, the air-entraining and the workability of mixtures were maintained constant at 0.38, 4.5% and 150 mm respectively. Test results indicated that in both methods, all tested concretes according to EN 1338: 2005 could be classified to 4-the highest class of abrasion resistance. In reference test of the Wide Wheel fly ash quality and quantity not influences abrasion resistance. However, in alternative, Böhme test abrasion resistance lowering with growth quantity of fly ash in binder, while loss of ignition of fly ash no influenced abrasion resistance. There were no correlation between the abrasion resistance and the compressive strength.

Structural Behaviour of Ferrogeopolymer Slabs under Flexure

2016 ◽  
Vol 866 ◽  
pp. 109-113
Author(s):  
Rathinam Kumutha ◽  
Kanagarajan Vijai ◽  
P. Rajeswaran
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Mild Steel ◽  
Double Layers ◽  
Fine Aggregate ◽  
Test Results ◽  
Structural Behaviour ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio ◽  
The Individual

The main objective of this paper was to present the results of experimental investigation carried out to study the structural behaviour of ferrogeopolymer elements under flexure. Initially the properties of geopolymeric binder prepared using the source materials such as Fly ash and Ground Granulated Blast Furnace Slag (GGBS) without conventional cement have been investigated. The different parameters considered in this study are the ratio of binder to fine aggregate (1:2 and1:3) and the ratio of Na2SiO3 to NaOH solutions (2.0 and 2.5). The various combinations of Fly ash and GGBS considered are 90% & 10% and 80% & 20%. The alkaline liquid to binder ratio is fixed as 0.45. The individual properties of mortar such as Compressive Strength and Density were determined as per relevant Indian standards. The geopolymer concrete mix that gives the highest compressive strength was used to cast the ferrogeopolymer structural slabs. Four numbers of rectangular slabs of size 800 mm x 300 mm x 25 mm were prepared with two types of meshes such as mild steel and galvanized iron weld mesh with single and double layers. Based on the test results Load-Deflection curves were drawn and the effectiveness of mild steel and galvanized iron weld meshes was compared from the characteristics such as first crack load, ultimate load, energy absorption and ductility.

scholarly journals Frost resistance of concretes containing ground granulated blast-furnace slag

2018 ◽  
Vol 163 ◽  
pp. 05001 ◽  
Author(s):  
Paweł Łukowski ◽  
Ali Salih ◽  
Joanna J. Sokołowska
Keyword(s):  
Blast Furnace ◽  
Frost Resistance ◽  
Blast Furnace Slag ◽  
Hydraulic Properties ◽  
Freezing And Thawing ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio ◽  
Water To Binder Ratio ◽  
Furnace Slag ◽  
Research Show

The paper deals with the influence of addition of ground granulated blast-furnace slag (GGBS) on the frost resistance of concrete. GGBS is a valuable modifier of concrete, having the latent hydraulic properties and particularly improving the chemical resistance of concrete. However, the performance of concretes with blast-furnace slag under freezing and thawing action is still not explained fully and remains a subject to discussion. The authors have investigated the concretes containing various amounts of GGBS and the portland cement CEM I, with various values of water to binder ratio, with and without the use of air-entraining admixture. The results of research show that the addition of blast-furnace slag causes some worsening of the frost resistance of concrete. The extent of this worsening depends on the water to binder ratio and the aeration of the concrete. However, even under the least favourable conditions, the concretes with GGBS addition have met the requirements of frost resistance after 200 cycles of freezing and thawing, given in the Standard PN-B-06265.

scholarly journals Practical Prediction Models of Tensile Strength and Reinforcement-Concrete Bond Strength of Low-Calcium Fly Ash Geopolymer Concrete

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 875
Author(s):  
Chenchen Luan ◽  
Qingyuan Wang ◽  
Fuhua Yang ◽  
Kuanyu Zhang ◽  
Nodir Utashev ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
Bond Strength ◽  
Prediction Models ◽  
Splitting Tensile Strength ◽  
Geopolymer Concrete ◽  
Structural Factors ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Low Calcium

There have been a few attempts to develop prediction models of splitting tensile strength and reinforcement-concrete bond strength of FAGC (low-calcium fly ash geopolymer concrete), however, no model can be used as a design equation. Therefore, this paper aimed to provide practical prediction models. Using 115 test results for splitting tensile strength and 147 test results for bond strength from experiments and previous literature, considering the effect of size and shape on strength and structural factors on bond strength, this paper developed and verified updated prediction models and the 90% prediction intervals by regression analysis. The models can be used as design equations and applied for estimating the cracking behaviors and calculating the design anchorage length of reinforced FAGC beams. The strength models of PCC (Portland cement concrete) overestimate the splitting tensile strength and reinforcement-concrete bond strength of FAGC, so PCC’s models are not recommended as the design equations.

Effect of Fly Ash and Nano-CaCO3 on the Viscosity of Cement Paste

2013 ◽  
Vol 357-360 ◽  
pp. 968-971 ◽  
Author(s):  
Ren Juan Sun ◽  
Zhi Qin Zhao ◽  
Da Wei Huang ◽  
Gong Feng Xin ◽  
Shan Shan Wei ◽  
...  
Keyword(s):  
Fly Ash ◽  
Cement Paste ◽  
Bingham Model ◽  
Reduced Viscosity ◽  
Binder Ratio ◽  
Water To Binder Ratio

The effect of fly ash and nanoCaCO3 on the viscosity of pastes was studied. The rheological value of cement paste was determined by the rotation rheometer NXS-11B. In the study, five different dosages (0%, 20%, 30%, 40%, and 50%) of fly ash and three levels of nanoCaCO3, 0.5%, 1%, and 2.5%, were considered. Viscosity of the pastes, made with fly ash and nanoCaCO3 at a constant water-to-binder ratio of 0.35, were measured and analyzed. The results indicate that the pastes with fly ash or/and nanoCaCO3 still fit the Bingham model. The addition of fly ash reduced viscosity, however, the addition of nanoCaCO3 increased viscosity. The effect of nanoCaCO3 is more significantly than fly ash on viscosity.

High Performance Concrete with Ternary Binders

2018 ◽  
Vol 761 ◽  
pp. 120-123 ◽  
Author(s):  
Vlastimil Bílek ◽  
David Pytlík ◽  
Marketa Bambuchova
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Silica Fume ◽  
High Performance ◽  
Ordinary Portland Cement ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Binder Ratio ◽  
Water To Binder Ratio ◽  
Condensed Silica Fume

Use a ternary binder for production of a high performance concrete with a compressive strengths between 120 and 170 MPa is presented. The water to binder ratio of the concrete is 0.225 and the binder is composed of Ordinary Portland Cement (OPC), condensed silica fume (CSF), ground limestone (L), fly ash (FA) and metakaoline (MK). The dosage of (M + CSF) is kept at a constant level for a better workability of fresh concrete. Different workability, flexural and compressive strengths were obtained for concretes with a constant cement and a metakaoline dosage, and for a constant dosage (FA + L) but a different ratio FA / L. An optimum composition was found and concretes for other tests were designed using this composition.

The Use of Recycled Aggregate Sludge for the Preparation of GGBFS and Fly Ash Based Geopolymer

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1486
Author(s):  
Yi-Chen Chen ◽  
Wei-Hao Lee ◽  
Yung-Chin Ding
Keyword(s):  
Fly Ash ◽  
Environmental Concern ◽  
Waste Product ◽  
Recycled Aggregate ◽  
Test Results ◽  
Granulated Blast Furnace Slag ◽  
Mechanical And Physical Properties ◽  
Preliminary Study ◽  
Solid Liquid ◽  
High Treatment

Aggregate sludge is a waste product produced from crushing, screening, and washing processes at aggregate plants. Because of the large quantity and high treatment cost of this sludge, it cannot be disposed of as landfill, and thus, has caused environmental concern over the years in Taiwan. In this preliminary study, the recycled aggregate sludge was reutilized for construction applications through the geopolymerization process. The ground granulated blast furnace slag (GGBFS) and fly ash (FA) were selected as alkaline activated materials for the fabrication of sludge geopolymer. Several process parameters that may affect the mechanical and physical properties of geopolymer were investigated. These parameters are sludge/GGBFS/FA ratios, solid/liquid (alkali solution) ratio, the molarity of NaOH, and curing time. According to the test results, the compressive strength of geopolymer specimens (70/30 sludge/GGBFS ratios) made with 4 M and 6 M NaOH can reach 39.17 MPa and 43.6 MPa after 28 days of curing. The specimen made with 60/40 sludge/GGBFS ratios has a strength of 61.3 MPa. After replacing GGBFS with 10% fly ash (70/20/10 sludge/GGBFS/FA), the strength of the specimen can also reach 43 MPa. According to the test results obtained in this study, it was found that the higher the NaOH concentration, the higher the strength of the geopolymer, and the GGBFS also can contribute more to the mechanical properties of geopolymer than fly ash. This preliminary study suggests that it is possible to reutilize aggregate sludge for construction applications and solve its environmental disposal problem.

Prediction Model for Cementing Efficiency of Fly Ash Concrete by Statistical Analyses

2011 ◽  
Vol 250-253 ◽  
pp. 1293-1296 ◽  
Author(s):  
Hong Bum Cho ◽  
Nam Yong Jee
Keyword(s):  
Fly Ash ◽  
Prediction Model ◽  
Statistical Analyses ◽  
Test Results ◽  
Construction Sites ◽  
K Value ◽  
Fly Ash Concrete ◽  
Mix Proportion ◽  
Wide Range ◽  
Binder Ratio

This paper offers the model that can estimate the cementing efficiency of fly ash (k value) based on a mix proportion of concrete containing fly ash (FA). The prediction model was derived using various statistical analyses, based on a wide range of mix proportions and a number of strength test results of ready mixed concretes used in eight construction sites. The k value increases with increasing water-binder ratio. As the FA replacement ratios increase, the k value increases at FA replacement ratios of less than 15%, but decreases at ratios of 15% or more. The k values obtained from the cementing efficiency estimate model range from 0.1 to 2.1.

scholarly journals Early Strength Development of Soft Clay Stabilized by One-Part Ground Granulated Blast Furnace Slag and Fly Ash-Based Geopolymer

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiyao Zheng ◽  
Jun Wu
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Soft Clay ◽  
Strength Development ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio ◽  
Early Strength ◽  
Furnace Slag ◽  
Water Binder Ratio

One-part or “just add water” geopolymer is a cementitious material, which is friendly to environment and users in applications. However, the mechanical behavior of the soft soil stabilized by one-part geopolymer is not well acknowledged. In this study, soft clay was stabilized with ground granulated blast furnace slag (GGBFS) and fly ash (FA)-based geopolymer, which is a mixture of solid aluminosilicate precursor (Al-Si raw materials: GGBFS and FA), solid alkali activator, and water. The objective was to adopt one-part geopolymer as an alternative soil binder to completely replace ordinary Portland cement (OPC) for stabilizing the soft clay and evaluate the effect of the factors (i.e., GBFS/FA ratio in Al-Si precursor, activator/Al-Si precursor ratio, and water/binder ratio) that influenced the early strength. Results showed that the increase of the FA content in the Al-Si precursor increased the unconfined compressive strength (UCS) values significantly through the geopolymerization process. The highest UCS values were achieved with 90% GGBFS to 10% FA in the precursor when the activator/precursor and water/binder ratio is 0.15 and 0.7, respectively. The UCS values of geopolymer-stabilized clay could reach 1.5 MPa at 14 days at ambient temperature, which is much higher than that of OPC-stabilized clay. The microstructure and mineralogy analyses indicated that the prolific hydration products, such as calcium silicate hydrate (C-S-H), calcium aluminum hydrate (C-A-H), and calcium aluminum silicate hydrate (C-A-S-H), contributed greatly to strengthen the soft clay by forming the soil skeleton and infilling among clay particles, while sodium aluminosilicate (N-A-S-H) gel is only served to fill the part of porosities in the soil and cannot effectively enhance the UCS of the one-part geopolymer-stabilized soft clay. This paper results suggested that one-part GGBFS-FA–based geopolymers have the potential to replace OPC in the manufacture of stabilized soft clay.

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