Thermal Conductivity of Controlled Low Strength Material (CLSM) Made Entirely from By-Products

2018 ◽  
Vol 773 ◽  
pp. 244-248
Author(s):  
Tan Manh Do ◽  
Young Sang Kim ◽  
Gyeong O Kang ◽  
My Quoc Dang ◽  
Thien Quoc Tran
Keyword(s):  
Thermal Conductivity ◽  
Red Mud ◽  
Setting Time ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Strength Material ◽  
Curing Condition ◽  
Low Strength ◽  
Controlled Low Strength Material ◽  
By Products

Various by-products generated from thermal power plants and chemical industries have considerably economic and environmental impacts in South Korea. This study focuses on evaluating thermal conductivity of controlled low strength material (CLSM) made entirely from by-products (e.g., coal ash, gypsum, red mud). In the experimental program, pond ash is used as a full replacement of natural sand whereas fly ash activated by a little lime, red mud, and gypsum is the main binder in the production of CLSM. Various laboratory tests including flowability, bleeding, initial setting time, and unconfined compressive strength were performed on the prepared CLSM mixtures to determine its general characteristics. Thermal conductivity is then measured subjected to saturated curing condition (SC) and room temperature curing condition (RTC). As a result, all general characteristics meet the specification of CLSM reported in ACI 229R by controlling the ratio of gypsum to red mud. In particular, the good flowability of higher than 20 cm is observed as the G/Rm ratio of smaller than 1.33. The bleeding values, ranging from 0.30% to 2.70%, fall into the bleeding requirement of CLSM of less than 5%. Moreover, the initial setting time and strength results are also in the acceptable specification of general CLSM in ACI 229R. Eventually, the thermal conductivity of the proposed CLSM was in the range of 0.84–0.87 (W/mK) and these values were considerably affected by the saturation states and curing conditions rather than binder proportion.

Evaluation of Fresh Properties of Controlled Low-Strength Material Produced from Water Treatment Sludge-Fly Ash-Slag Mixture Using Alkaline Activation

2018 ◽  
Vol 878 ◽  
pp. 28-34
Author(s):  
Chao Lung Hwang ◽  
Chi Hung Chiang ◽  
Trong Phuoc Huynh ◽  
Bo Jyun Jhang
Keyword(s):  
Fly Ash ◽  
Water Treatment ◽  
Setting Time ◽  
Water Treatment Sludge ◽  
Fresh Properties ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Strength Material ◽  
Drop Time ◽  
Low Strength

This study used a sodium hydroxide (NaOH) solution to activate a mixture of water treatment sludge, fly ash, and slag, in order to produce a new alkali-activated controlled low-strength material (CLSM). Fresh properties of this new CLSM were investigated through the tests of workability, setting time, and ball drop time. Test results show that the addition of water treatment sludge (WTS) decreased workability. In addition, the addition of such WTS increased initial setting time and ball drop time, whereas the alkali equivalent (AE) shortened the initial setting time and ball drop time. At a liquid-to-solid ratio (L/S) of 0.9, a WTS content of 10%, and an alkali equivalent of 9%, the fresh properties for the CLSM conforms to the design principles and provisions of the Public Works Department, Taipei City Government, and is ideal for road construction in order to reduce traffic impact.

scholarly journals Experimental study on the application of red mud to controlled low strength material made of excavated soil

2021 ◽  
Vol 2045 (1) ◽  
pp. 012027
Author(s):  
X H Kong ◽  
S Cui ◽  
L H Chen ◽  
X H Wang
Keyword(s):  
Red Mud ◽  
Strength Test ◽  
Positive Role ◽  
Bleeding Rate ◽  
Compressive Strength Test ◽  
Strength Material ◽  
Low Strength ◽  
Controlled Low Strength Material ◽  
Alumina Industry ◽  
The Relationship

Abstract To improve the resource utilization of solid waste, excavation abandoned soil and red mud, a by-product of alumina industry, were introduced into the preparation of controlled low strength material (CLSM). By carrying out the flowability test, bleeding test and compressive strength test, the relationship between properties of CLSM mixture and the amount of red mud was analysed. The experiment results indicate that the flowability and bleeding rate of the mixture decrease with the increase of red mud content. When the red mud content is less than 20%, the mixture shows good flowability. The addition of red mud can accelerate the completion time of bleeding and play a positive role in the bleeding stability of the mixture. When the red mud content is 10%, the strength of the mixture reaches the maximum, while the strength of the mixture with other contents decreases with the increase of red mud content. For the CLSM made of excavated soil, red mud has a good application prospect in terms of bleeding stability and strength.

Characteristics of Alkali-Activated Controlled Low-Strength Material Derived from Red Mud-Slag Blends

2017 ◽  
Vol 753 ◽  
pp. 343-348
Author(s):  
Chao Lung Hwang ◽  
Trong Phuoc Huynh
Keyword(s):  
Compressive Strength ◽  
Red Mud ◽  
Raw Materials ◽  
Setting Time ◽  
Public Works ◽  
Granulated Blast Furnace Slag ◽  
Naoh Solution ◽  
Strength Material ◽  
Low Strength ◽  
Alkali Activated

This investigation evaluates the characteristics of alkali-activated controlled low-strength materials (CLSM) that were produced using a mixture of red mud (RM) and ground granulated blast-furnace slag (GGBFS) with different RM-to-GGBFS weight ratios (100/0, 90/10, 80/20, and 70/30). A sodium hydroxide (NaOH) solution of 5M concentration was used as an activator. Characteristics of raw materials were checked carefully before using. The effects of GGBFS content on both fresh and hardened properties of the CLSM were evaluated through the tests of flowability, setting time, and compressive strength. Additionally, a scanning electron microscope (SEM) was used to examine the microstructural properties of the CLSM. Experimental results show that using more GGBFS in the mixture reduces flowability and increases the compressive strength of the CLSM. Moreover, the setting time of the fresh CLSM is associated positively with GGBFS content. Further, analysis of the optimal mixture was conducted basing on the test results. Thus, the properties of the CLSM sample containing 80% RM and 20% GGBFS conformed well to the requirements of the Public Works Department, Taipei Government, Taiwan. The results of this study further support the potential use of RM-GGBFS blends for the production of alkali-activated CLSM.

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