Production and engineering application of C60 high-performance pump pebble concrete containing ultra-fine fly ash

2008 ◽  
Vol 35 (8) ◽  
pp. 757-763 ◽  
Author(s):  
Ying Li Gao ◽  
Bao Guo Ma ◽  
Shi Qiong Zhou
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Engineering Application ◽  
Chloride Ion ◽  
Test Method ◽  
Ordinary Concrete ◽  
Second Stage ◽  
Chloride Ion Penetration ◽  
Engineering Requirement ◽  
Better Than

C60 grade high-performance pump concrete incorporating river pebbles and ultra-fine fly ash (UFA) was successfully prepared, with UFA replacing 30% of the cement, for the second-stage of construction of the Hunan Xiangtan Power Plant. Some of the properties of this pump concrete were studied using both laboratory and on-site testing. The results indicated that workability of UFA concrete was excellent. The initial slump surpassed 180 mm, and the slump loss was small. The 28 d strength of the concrete met the engineering requirement of conforming to C60 strength grade. It is shown that the resistance–chloride ion penetration of UFA pump concrete is better than that of ordinary concrete in terms of Association for Testing and Materials test method C1202-94. Dry shrinkage of concrete slightly reduced with the addition of UFA, and UFA concrete shows better crack resistance compared with ordinary concrete. The production technology of UFA pump pebble concrete is summarized based on test and engineering applications.

The Frost Resistance of LYTAG Concrete

2014 ◽  
Vol 936 ◽  
pp. 1419-1422
Author(s):  
Ai Lian Zhang ◽  
Lin Chun Zhang
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Frost Resistance ◽  
Interfacial Transition Zone ◽  
Test Method ◽  
Mineral Admixture ◽  
Cement Stone ◽  
Normal Density ◽  
Ordinary Concrete ◽  
Better Than

This article studies the frost resistance of LYTAG concrete and ordinary concrete respectively used the RILEM recommended test method (CIF) about frost resistance of concrete. The results indicate that the single surface's frost resistance of Lytag concrete with mineral admixture is much better than normal density concrete's. And the rank of the single surface's frost resistance at 56 cycles of Lytag concrete with different mineral admixture is: silica fume and slag> silica fume and fly ash>slag and fly ash>silica fume>fly ash>slag. The important reasons why LYTAG concrete has good frost resistance is that the scope of blending interfacial transition zone of LYTAG concrete between aggregate ceramsite and cement stone was significantly smaller than ordinary concrete.

Study on Resistance to Chloride Ion Penetration of High Performance Concrete for High Speed Railway Bridge Pile

2010 ◽  
Vol 150-151 ◽  
pp. 542-546
Author(s):  
Sheng Ai Cui ◽  
Yue Zhong Ye ◽  
Fei Fu ◽  
Zhi Feng Liu
Keyword(s):  
High Speed ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Ion ◽  
Chloride Salt ◽  
High Speed Railway ◽  
Chloride Ion Penetration ◽  
Study Results ◽  
Better Than ◽  
Ion Penetration

Taking bridge pile of high speed railway as background, resistance to chloride ion penetration of high performance concrete is studied. Theoretical analysis and experimental research of chloride ion penetration are carried out for double-doped mineral (fly ash and slag powder) concrete, C35 single mineral and preservative double-doped concrete, and C35 two kinds of minerals and preservative composite concrete. In addition, the test results are compared and analyzed. Study results show: chloride ion penetration grade of double-doped mineral concrete (C35, C40, C45 and C50) is very low. Resistances to chloride ion penetration of C35 single mineral and preservative double-doped concrete are all poor overall, so the scheme is infeasible. By performance comparison of resistance to chloride ion penetration, C35 two kinds of minerals and solid preservative composite concrete is obviously better than C35 two kinds of minerals and liquid preservative composite concrete , meanwhile obviously better than C35 double-doped mineral concrete, and very close to C50 double-doped mineral concrete. And, it can meet resistance to chloride ion penetration requirement under the corrosion environments along the high speed railway line and can be used as high performance concrete to resist chloride salt.

Permeability of Concrete Containing Air-Entraining and Mineral Admixtures

2011 ◽  
Vol 250-253 ◽  
pp. 425-429
Author(s):  
Wei Rong Huang ◽  
De Bin Yang ◽  
Jian Ting Zhou ◽  
Li Li ◽  
Wei Na Zhang
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Chloride Ion ◽  
Mineral Admixtures ◽  
Cement Ratio ◽  
Air Content ◽  
Chloride Ion Penetration ◽  
Saline Area ◽  
Electric Flux ◽  
Better Than

In this paper, the performance of concrete is studied through different water-cement ratio, different air-content, different mineral admixtures, different admixture contents, examined the mechanical properties of concrete, electric flux and chloride ion penetration depth of different mix concrete. The results show that, decreasing w/c ratio, proper air content, adding mineral admixtures can improve the resistance of chloride-permeation. Within some contents, the chloride-permeation resistance using silicides is better than that of fly-ash or slag. On this basis, the proper scheme of mix ratio used in saline area is recommended: the air-content is 3%～5%, the content of fly-ash or slag is 20%～30%, the content of silicides is 6%～8%, and double mixed with silicides.

Test and Study on Green High-Performance Marine Concrete Containing Ultra-Fine Limestone Powder

2013 ◽  
Vol 368-370 ◽  
pp. 1112-1117
Author(s):  
Jin Hui Li ◽  
Liu Qing Tu ◽  
Ke Xin Liu ◽  
Yun Pang Jiao ◽  
Ming Qing Qin
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Mechanical Performance ◽  
Chloride Ion ◽  
Limestone Powder ◽  
Ion Permeability ◽  
High Quality ◽  
Cracking Resistance ◽  
Slag Powder ◽  
Marine Concrete

In order to solve the environment pollution of limestone powder during production of limestone manufactured sand and gravel and problem of lack of high quality fly ash or slag powder in ocean engineering, ultra-fine limestone powder was selected for preparation of green high-performance marine concrete containing fly ash and limestone powder and that containing slag powder and limestone powder for tests on workability, mechanical performance, thermal performance, shrinkage, and resistance to cracking and chloride ion permeability. And comparison was made between such green high-performance concrete and conventional marine concrete containing fly ash and slag powder. Moreover, the mechanism of green high-performance marine concrete was preliminary studied. Results showed that ultra-fine limestone powder with average particle size around 10μm had significant water reducing function and could improve early strength of concrete. C50 high-performance marine concrete prepared with 30% fly ash and 20% limestone powder or with 30% slag powder and 30% limestone powder required water less than 130kg/m3, and showed excellent workability with 28d compressive strength above 60MPa, 56d dry shrinkage rate below 300με, cracking resistance of grade V, 56d chloride ion diffusion coefficient not exceeding 2.5×10-12m2/s. Mechanical performance and resistance to chloride ion permeability of limestone powder marine concrete were quite equivalent to those of conventional marine concrete. But it had better workability, volume stability and cracking resistance. Moreover, it can serve as a solution to the lack of high quality fly ash and slag powder.

scholarly journals Recycled Plastic and Cork Waste for Structural Lightweight Concrete Production

2019 ◽  
Vol 11 (7) ◽  
pp. 1876 ◽  
Author(s):  
Carlos Parra ◽  
Eva M. Sánchez ◽  
Isabel Miñano ◽  
Francisco Benito ◽  
Pilar Hidalgo
Keyword(s):  
Compression Strength ◽  
High Performance ◽  
Lightweight Concrete ◽  
Chloride Ion ◽  
Total Porosity ◽  
Lightweight Aggregates ◽  
Chloride Ion Penetration ◽  
Concrete Production ◽  
Risk Areas ◽  
Strength And Durability

The use of waste materials as lightweight aggregates in concrete is highly recommended in seismic risk areas and environmentally recommended. However, reaching the strength needed for the concrete to be used structurally may be challenging. In this study four dosages were assayed: the first two-specimen had high cement content (550 and 700 kg/m3 respectively), Nanosilica, fly ash and superplasticizer. These samples were high performance, reaching a strength of 100MPa at 90 days. The other two mixtures were identical but replaced 48% of the aggregates with recycled lightweight aggregates (30% polypropylene, 18.5% cork). To estimate its strength and durability the mixtures were subjected to several tests. Compression strength, elasticity modulus, mercury intrusion porosimetry, carbonation, attack by chlorides, and penetration of water under pressure were analyzed. The compression strength and density of the lightweight mixtures were reduced 68% and 19% respectively; nonetheless, both retained valid levels for structural use (over 30MPa at 90 days). Results, such as the total porosity between 9.83% and 17.75% or the chloride ion penetration between 8.6 and 5.9mm, suggest that the durability of these concretes, including the lightweight ones, is bound to be very high thanks to a very low porosity and high resistance to chemical attacks.

scholarly journals The Influence of Crystalline Admixtures on the Properties and Microstructure of Mortar Containing By-Products

Buildings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 146
Author(s):  
Jakub Hodul ◽  
Nikol Žižková ◽  
Ruben Paul Borg
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Chloride Ion ◽  
Capillary Suction ◽  
Chloride Ion Penetration ◽  
Chloride Migration ◽  
Cement Mortars ◽  
Polymer Mortar ◽  
By Products ◽  
Ion Penetration

Crystalline admixtures and industrial by-products can be used in cement-based materials in order to improve their mechanical properties. The research examined long-term curing and the exposure to environmental actions of polymer–cement mortars with crystalline admixture (CA) and different by-products, including Bengħisa fly ash and Globigerina limestone waste filler. The by-products were introduced as a percentage replacement of the cement. A crystallization additive was also added to the mixtures in order to monitor the improvement in durability properties. The mechanical properties of the mortar were assessed, with 20% replacement of cement with fly ash resulting in the highest compressive strength after 540 days. The performance was analyzed with respect to various properties including permeable porosity, capillary suction, rapid chloride ion penetration and chloride migration coefficient. It was noted that the addition of fly ash and crystalline admixture significantly reduced the chloride ion penetration into the structure of the polymer cement mortar, resulting in improved durability. A microstructure investigation was conducted on the samples through Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS). Crystals forming through the crystalline admixture in the porous structure of the material were clearly observed, contributing to the improved properties of the cement-based polymer mortar.

scholarly journals Influence of Fly Ash Additive on the Properties of Concrete with Slag Cement

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3265 ◽  
Author(s):  
Anna Szcześniak ◽  
Jacek Zychowicz ◽  
Adam Stolarski
Keyword(s):  
Fly Ash ◽  
Chloride Ion ◽  
High Strength ◽  
Experimental Tests ◽  
Chloride Ions ◽  
Strength Increase ◽  
Slag Cement ◽  
Initial Strength ◽  
Chloride Ion Penetration ◽  
The Impact

This paper presents research on the impact of fly ash addition on selected physical and mechanical parameters of concrete made with slag cement. Experimental tests were carried out to measure the migration of chloride ions in concrete, the tightness of concrete exposed to water under pressure, and the compressive strength and tensile strength of concrete during splitting. Six series of concrete mixes made with CEM IIIA 42.5 and 32.5 cement were tested. The base concrete mix was modified by adding fly ash as a partial cement substitute in the amounts of 25% and 33%. A comparative analysis of the obtained results indicates a significant improvement in tightness, especially in concrete based on CEM IIIA 32.5 cement and resistance to chloride ion penetration for the concretes containing fly ash additive. In the concretes containing fly ash additive, a slower rate of initial strength increase and high strength over a long period of maturation are shown. In accordance with the presented research results, it is suggested that changes to the European standardization system be considered, to allow the use of fly ash additive in concrete made with CEM IIIA 42.5 or 32.5 cement classes. Such a solution is not currently acceptable in standards in some European Countries.

Influence of Artificial Aggregates on the ITZ's Microstructure of Recycling Concrete

2013 ◽  
Vol 743-744 ◽  
pp. 180-185
Author(s):  
Jun Hua Zhang ◽  
Zong Hui Zhou ◽  
De Cheng Zhang ◽  
Xin Cheng
Keyword(s):  
Fly Ash ◽  
Mineral Composition ◽  
High Performance ◽  
Raw Materials ◽  
Steel Slag ◽  
Interfacial Transition Zone ◽  
Hydration Products ◽  
Ordinary Concrete ◽  
Natural Aggregates ◽  
Furnace Slag

Artificial aggregates with high-performance were prepared by the methods including steel slag, furnace slag, fly ash and coal gangue, and the recycling concrete was prepared by artificial aggregates instead of natural aggregates. This kind of concrete abandoned was able to completely regenerate cement, which will make the reuse of concrete possible. The composition and characteristics of the artificial aggregates will produce a significant effect on the interfacial transition zone (ITZ) in recycling concrete. The morphological features and mineral composition of three artificial aggregates were analyzed by SEM and XRD, and the ITZ of three recycling concrete and one ordinary concrete was investigated by SEM and EDS. The results showed that compared with ordinary concrete, although the recycling concretes ITZ had a small amount of CH crystal, most of the space was filled with dense hydration products. The interface width was 40μm, which less than 50μm of ordinary concrete. Artificial aggregates with different ratio of raw materials had a great effect on recycling concretes ITZ. The ITZ of recycling concrete prepared with 30% steel slag, 50% furnace slag, 20% fly ash had the smallest Ca/Si and much more C-S-H. the structure of ITZ was much denser and the microstructure was relatively better.

Sign in / Sign up

Export Citation Format

Share Document