scholarly journals Effect of Alkaline Activator to Fly Ash Ratio for Geopolymer Stabilized Soil

2017 ◽  
Vol 97 ◽  
pp. 01012 ◽  
Author(s):  
Muhammad Sofian Abdullah ◽  
Fauziah Ahmad
Keyword(s):  
Fly Ash ◽  
Stabilized Soil ◽  
Alkaline Activator

scholarly journals Experimental Investigation of Unconfined Compression Strength and Microstructure Characteristics of Slag and Fly Ash-Based Geopolymer Stabilized Riverside Soft Soil

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 307
Author(s):  
Zhengdong Luo ◽  
Biao Luo ◽  
Yufei Zhao ◽  
Xinyu Li ◽  
Yonghua Su ◽  
...  
Keyword(s):  
Fly Ash ◽  
Soft Soil ◽  
Environmental Cost ◽  
Unconfined Compression ◽  
High Resource ◽  
Stabilized Soil ◽  
Resource Cost ◽  
High Reduction ◽  
Alkaline Activator ◽  
Reduction Cost

To solve the issues of insufficient early strength of cement stabilized soil and high resource cost, high reduction cost, and high environmental cost induced by the application of cement, the slag and fly ash-based geopolymer was adopted as the stabilizer to treat riverside soft soil. This study mainly investigated the effects of stabilizer content, slag-to-fly ash ratio, and alkaline activator content on the strength of geopolymer stabilized soils with different curing ages. Unconfined compressive strength (UCS), scanning electron microscope (SEM), and X-ray energy spectrum analysis (EDS) tests were carried out. The results show that the stabilizer content, slag–fly ash ratio, and alkaline activator content have a decisive influence on the UCS of geopolymer-stabilized soil. The mix-proportions scheme of geopolymer stabilized riverside soft soil, with a geopolymer content of 15%, a slag–fly ash ratio of 80:20, and an alkaline activator content of 30%, is considered optimum. It is proven by SEM that the uniformly distributed gelatinous products formed in the geopolymer-stabilized soil bind the soil particles tightly. Moreover, the EDS analysis confirms that the gelatinous products are mainly composed of C-S-H gel and sodium-based aluminosilicate (N-A-S-H).

Mechanics Properties of the Lime-Fly Ash Stabilized Soil for Pavement Structures

2012 ◽  
Vol 594-597 ◽  
pp. 1445-1448
Author(s):  
Tao Cheng ◽  
Ke Qin Yan
Keyword(s):  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Flexible Pavement ◽  
Rigid Pavement ◽  
Test Compaction ◽  
Mix Proportion ◽  
Stabilized Soil ◽  
Pavement Structures ◽  
Optimum Water ◽  
Water Contents

Mechanics properties of lime- fly ash stabilized soil are investigated. First, the chemical composition of fly ash are analyzed by spectral analysis test. Compaction experiments of all mix proportion projects are carried out in different water conditions to obtain the optimum water contents. Then the optimum mix proportion is obtained by the unconfined compressive strength and the compression rebound modulus test. Finally, the pavement structures design for a highway of lime- fly ash stabilized soil road sub-base is done. By the comparison, a conclusion can be drawn that lime-fly ash stabilized soil is suitable for flexible pavement or semi-rigid pavement because of its good strength and rigidity which can effectively reduce thickness of the lower pavement and basic deflection.

scholarly journals Ultimate Bearing Capacity of Stabilized Soil in Pavements

2020 ◽  
Vol 9 (5) ◽  
pp. 2349-2351
Keyword(s):  
Fly Ash ◽  
Bearing Capacity ◽  
Coal Ash ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Base Layer ◽  
Plate Load Test ◽  
Rubber Powder ◽  
Stone Dust ◽  
Stabilized Soil

This paper discusses the Ultimate Bearing Capacity of a stabilized soil by using the fly ash, stone dust and rubber powder for design of a pavement. This paper will help in utilization of locally available waste materials to reuse in the subbase and subgrade layers of pavement. Rubber powder is a waste byproduct generated from the recycling of tires, and is not so easy for degradable, and hence leads to release of harmful gases when it tends to burn. Stone dust is a locally available waste generated product from quarries. The generation of stone dust is increasing day to day in large quantity. The huge quantity of stone dust storage amount will affect the quality of soil. Fly ash is waste combusted coal ash powder generated from the steamers of coal boilers with the burning of fuel gases together. In the sub grade layer the soil is mixed in different proportions with stone dust for hard foundation. In the sub base layer the soil is stabilized with the combination of rubber powder and fly ash. When the rubber powder and fly ash, mixed with water for compaction generates a bond between the soil particles to settle the air fields. In this paper various percentages of rubber powder, stone dust and fly ash with different samples for pavement is layered, and after that plate load test is conducted upon it.

scholarly journals Research on the Dynamic Mechanical Properties and Energy Dissipation of Expansive Soil Stabilized by Fly Ash and Lime

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Sheng-quan Zhou ◽  
Da-wei Zhou ◽  
Yong-fei Zhang ◽  
Wei-jian Wang ◽  
Dongwei Li
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Expansive Soil ◽  
Dynamic Mechanical Properties ◽  
Test Results ◽  
Absorbed Energy ◽  
Dynamic Mechanical ◽  
Stabilized Soil ◽  
Dynamic Compressive Strength

To probe into the dynamic mechanical properties of expansive soil stabilized by fly ash and lime under impact load, the split-Hopkinson pressure bar (SHPB) test was carried out in this study. An analysis was made on the dynamic mechanical property and final fracture morphology of stabilized soil, and the failure mechanism was also explored from the perspective of energy dissipation. According to the test results, under the impact pressure of 0.2 MPa, plain soil and pure fly ash-stabilized soil exhibit strong plasticity. After the addition of lime, the stabilized soil shows obvious brittle failure. The dynamic compressive strength and absorbed energy of stabilized soil first increase and then decrease with the change of mix proportions. Both the dynamic compressive strength and the absorbed energy reach the peak value at the content of 20% fly ash and 5% lime (20% F + 5% L). In the process of the test, most of the incident energy is reflected back to the incident bar. The absorbed energy of stabilized soil increases linearly with the rise of dynamic compressive strength, while the absorbed energy is negatively correlated with the fractal dimension. The fractal dimension of pore morphology of the plain soil is lower than that of the fly ash-lime combined stabilized soil when it comes to the two different magnification ratios. The test results indicate that the modifier content of 20% F + 5% L can significantly improve the dynamic mechanical properties of the expansive soil.

scholarly journals Alkali-activated concretes based on fly ash and blast furnace slag: Compressive strength, water absorption and chloride permeability

2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Daniela Eugenia Angulo-Ramírez ◽  
William Gustavo Valencia-Saavedra ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Water Absorption ◽  
Blast Furnace Slag ◽  
Construction Materials ◽  
Chloride Ion ◽  
Chloride Permeability ◽  
Alkaline Activator ◽  
Furnace Slag

Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.

Effect of Curing Time and Sintering to the Properties of Geopolymer Mortars

2017 ◽  
Vol 888 ◽  
pp. 184-187
Author(s):  
Salwa Ismail ◽  
Mohammad Faizal Mohd Razali ◽  
Izwan Johari ◽  
Zainal Arifin Ahmad ◽  
Shah Rizal Kasim
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Distilled Water ◽  
Curing Time ◽  
Pore Former ◽  
X Ray ◽  
Before And After ◽  
Naoh Solution ◽  
Added Water ◽  
Alkaline Activator

In this study, the geopolymer mortars were synthesized with fly ash (FA) and silica powder as aluminosilicate sources and a combination of sodium hydroxide (NaOH) solution, sodium silicate (Na2SiO3) solution and distilled water as alkaline activator. Commercial sago was used as a pore former in the mortars. The percentage of sago used were 10, 20 and 30 wt% of FA. The amount of added water used in each mixture was 5% by weight of FA, NaOH solution and Na2SiO3 solution. The formed geopolymer mortars were cured for 1, 3 and 7 days and sintered at 1000 °C. X-ray fluoresence (XRF) shown that FA contains higher amount of silica (SiO2) and alumina (Al2O3) which is important as aluminosilicate sources. The properties of the geopolymer mortars before and after sintered at 1000 °C have been investigated. The results show that geopolymer mortars with 10% of sago content with curing time of 7 days and sintered at 1000 °C give the highest compressive strength of 13.5 MPa.

The Effect of Curing Time on the Properties of Fly Ash-Based Geopolymer Bricks

2012 ◽  
Vol 626 ◽  
pp. 937-941 ◽  
Author(s):  
W.I. Wan Mastura ◽  
H. Kamarudin ◽  
I. Khairul Nizar ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
H. Mohammed
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Experimental Work ◽  
Base Material ◽  
Curing Time ◽  
Curing Conditions ◽  
Alkaline Activator

This paper reports the results of an experimental work conducted to investigate the effect of curing conditions on the properties of fly ash-based geopolymer bricks prepared by using fly ash as base material and combination of sodium hydroxide and sodium silicate as alkaline activator. The experiments were conducted by varying the curing time in the range of 1-24 hours respectively. The specimens cured for a period of 24 hours have presented the highest compressive strength for all ratio of fly ash to sand. For increasing curing time improve compressive strength and decreasing water absorption.

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