Development of high performance lightweight concrete using ultra high performance cementitious composite and different lightweight aggregates

2021 ◽  
Vol 124 ◽  
pp. 104277
Author(s):  
Jian-Xin Lu ◽  
Peiliang Shen ◽  
Hafiz Asad Ali ◽  
Chi Sun Poon
Keyword(s):  
High Performance ◽  
Lightweight Concrete ◽  
Lightweight Aggregates ◽  
Cementitious Composite

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 Low dosage nano-silica modification on lightweight aggregate concrete

2018 ◽  
Vol 8 ◽  
pp. 184798041876128 ◽  
Author(s):  
Pengyu Zhang ◽  
Ning Xie ◽  
Xin Cheng ◽  
Lichao Feng ◽  
Pengkun Hou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cement Paste ◽  
High Performance ◽  
Lightweight Concrete ◽  
Hydration Product ◽  
Lightweight Aggregate Concrete ◽  
Lightweight Aggregates ◽  
Hydration Products ◽  
Nano Silica ◽  
Low Dosage

Although the nano modification has been considered as a promising approach to enhance the mechanical properties of cement-based concrete, the investigation of low dosage nano modification on lightweight cement-based concrete is still very limited. In this study, the lightweight concrete, which was modified with low dosage nano-silica particles, were investigated. Non-prewetting and prewetting methods were used to prepare the lightweight concrete samples. The compressive and flexural strengths were tested to evaluate the modification effects of low dosage nano-silica on lightweight concrete. The microstructure analyses demonstrate that the hydration process of the cement paste can be changed with addition of nano-silica, and new types of hydration products have been observed in nano modified cementitious matrix. The interface between the lightweight aggregates and the cement paste can be reinforced by low dosage of nano-silica due to the new types of hydration products. However, relatively high dosage of nano-silica will reduce the modification effect because of the internal stress, which is resulted from the volume expansion of the new types of hydration product, at the interface of the lightweight aggregates and the cement paste. This study not only shows the possibility of low dosage nano modification on the mechanical properties enhancement of lightweight concrete but also provides potential modification mechanisms, which help to design and fabricate high-performance lightweight concrete materials.

Properties of Artificial Lightweight Aggregates (ALAs) Made of Dredged Soil Mixed with Waste Catalyst Slag

2012 ◽  
Vol 174-177 ◽  
pp. 1079-1085 ◽  
Author(s):  
Si Nae Jo ◽  
Yoo Tack Kim ◽  
Seung Gu Kang ◽  
Chang Sam Kim
Keyword(s):  
Specific Gravity ◽  
Water Absorption ◽  
Lightweight Concrete ◽  
Sintering Temperature ◽  
Thermal Power ◽  
Lightweight Aggregates ◽  
Dredged Soil ◽  
Porous Carriers ◽  
Black Core ◽  
Sintering Method

The artificial lightweight aggregates (ALAs) were manufactured using dredged soil produced at thermal power plant and waste catalyst slag by direct sintering method at 1050~1250°C for 10min. The ALAs of 100% dredged soil showed the black core phenomenon even at the low sintering temperature as 1050°C and become lightened by bloating pores in black core area with sintering temperature. On the other hand, the aggregates with 100% waste catalyst slag did not showed black coring and bloating phenomenon and had the low forming ability and many cracks inside. Adding the dredged soil to the waste catalyst slag decrease the specific gravity by promoting the black coring and bloating inside. The water absorption(%) of ALAs decreased with sintering temperature. The ALAs fabricated in this study showed the specific gravity of 0.8~2.0 and water absorption of 2~16% so it could be applied to various fields such as the lightweight concrete or the field of the porous carriers for purification of a contaminated soil or water.

Elastoplastic time history analysis of reinforced engineered cementitious composite or engineered cementitious composite–concrete composite frame under earthquake action

2016 ◽  
Vol 20 (4) ◽  
pp. 491-503 ◽  
Author(s):  
Fang Yuan ◽  
Jinlong Pan ◽  
Christopher KY Leung
Keyword(s):  
Cyclic Loading ◽  
High Performance ◽  
Time History ◽  
Frame Structure ◽  
Dissipated Energy ◽  
Seismic Resistance ◽  
Cementitious Composite ◽  
Engineered Cementitious Composite ◽  
Composite Frame ◽  
Story Drift

Engineered cementitious composite is a class of high-performance cementitious composites with pseudo-strain hardening behavior and excellent crack control capacity. Substitution of concrete with engineered cementitious composite can greatly reduce the cracking and durability problems associated with low tensile strength and brittleness of concrete and can significantly increase structural seismic resistance. In this article, a pair of beam–column joints with various matrix types has been tested under reversed cyclic loading to study the effect of substitution of concrete with engineered cementitious composite in the joint zone on the seismic behaviors of composite members. After that, a simplified constitutive model of engineered cementitious composite under cyclic loading is proposed, and the structural performance of steel reinforced engineered cementitious composite members is simulated by fiber beam elements. The accuracy of the model is verified with test data. Finally, three frame structures with different matrixes subjected to earthquake actions were numerically modeled to verify the contribution of ductile engineered cementitious composite material to structural seismic resistance. The seismic responses or failure mechanisms, deformation patterns, and energy dissipation capacities for each frame structure are analyzed and compared. The simulation results indicate that the application of engineered cementitious composite can reduce the maximum story drift ratio, and the distributions of the dissipated energy are more uniform along the building height when engineered cementitious composite is strategically used in ground columns and beam–column joints of the frame structure. The seismic performance of the reinforced engineered cementitious composite-concrete composite frame is found to be even better than the frame with all concrete replaced by engineered cementitious composite.

Research and Applying Evolution of High Efficient Water-Reducing Agent for High Performance Concrete

2012 ◽  
Vol 610-613 ◽  
pp. 573-576
Author(s):  
Zheng Jun Wang ◽  
Jia Bin Liang
Keyword(s):  
High Performance ◽  
Lightweight Concrete ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Reducing Agent ◽  
Mass Concrete ◽  
Green Concrete ◽  
High Efficient ◽  
Strength And Durability

This paper discusses the development of water-reducing agent and the present situation of the application of high performance concrete. The traditional concrete will be substituted by high performance concrete, green concrete. In the course of appearance of high performance and green, concrete admixtures plays an extremely important role. Concrete water-reducing agent is admixture of the main part. In the case of keeping liquidity, it can make water consumption reduce, so the concrete strength and durability can be improved. It is applicable to all kinds of industrial and civil construction engineering, and it can be applied to different strength grade of concrete. It has important significance for mass concrete engineering, marine building facilities, and component and product of high strength lightweight concrete.

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