Unconfined Compressive and Splitting Tensile Strength of Dredged Sediments Stabilized with Cement and Fly Ash

2020 ◽  
Vol 856 ◽  
pp. 367-375
Author(s):  
Hatairat Poorahong ◽  
Nunthanis Wongvatana ◽  
Pitthaya Jamsawang ◽  
Kamolwan Lueprasert ◽  
Kullachai Tantayopin ◽  
...  

The main objective of this study is to investigate the mechanical properties of dredged sediments, which are considered as waste from the process of removing sediments from the bottom of a dam's reservoir. The dredged sediments with stabilization can to be reused as construction and building materials in civil engineering works. The mechanical tests included unconfined compressive strength (UCS) and splitting tensile strength (STS) to understand the behavior of the dredged sediments stabilized with ordinary portland cement (OPC) type I and fly ash (FA). The overall test results indicated that OPC type I and FA were effective in stabilizing the sampled dredged sediments from two dams in northern Thailand. The stabilization with 10% FA content was found to be most effective for improving mechanical properties of the stabilized samples.

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 875
Author(s):  
Chenchen Luan ◽  
Qingyuan Wang ◽  
Fuhua Yang ◽  
Kuanyu Zhang ◽  
Nodir Utashev ◽  
...  

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.


2019 ◽  
Vol 276 ◽  
pp. 01014
Author(s):  
I Made Alit Karyawan Salain ◽  
I Nyoman Sutarja ◽  
Teguh Arifmawan Sudhiarta

This experimental study presents the properties of highperformance concrete (HPC) made by partially replacing type I Portland cement (OPC) with class C fly ash (CFA). The purpose of this study is to examine, with hydration time, the development of the compressive strength, the splitting tensile strength and the permeability of HPC utilizing different quantity of CFA. Four HPC mixtures, C1, C2, C3, and C4, were made by utilizing respectively 10%, 20%, 30% and 40% of CFA as replacement of OPC, by weight. One control mixture, C0, was made with 0% CFA. The mix proportion of HPC was 1.00 binder: 1.67 fine aggregate: 2.15 coarse aggregate with water to binder ratio 0.32. In each mixture, it was added 5% silica fume and 0.6% superplasticizer of the weight of the binder. Tests of HPC properties were realized at the age of 1, 3, 7, 28, and 90 days. The results indicate that CFA used to partially replace OPC in HPC shows adequate cementitious and pozzolanic properties. The compressive strength and the splitting tensile strength of HPC increase while the permeability coefficient decreases with increasing hydration time. It is found that the optimum replacement of OPC with CFA is 10%, however the replacement up to 20% is still acceptable to produce HPC having practically similar harden properties with control mixture. At this optimum replacement and after 90 days of hydration, the compressive strength, the splitting tensile strength and the permeability coefficient can reach 68.9 MPa, 8.3 MPa and 4.6 E-11 cm/sec respectively. These results are 109%, 101%, and 48% respectively of those of control mixture.


1994 ◽  
Vol 370 ◽  
Author(s):  
Manouchehr Hassanzadeh

AbstractThis study has determined the fracture mechanical properties of 9 types of rock, namely fine-, medium- and coarse-grained granites, gneiss, quartzite, diabase, gabbro, and fine- and coarse-grained limestones. Test results show among other things that quartzite has the highest compressive strength and fracture energy, while diabase has the highest splitting tensile strength and modulus of elasticity. Furthermore, the strength and fracture energy of the interfacial zone between the rocks and 6 different mortars have been determined. The results showed that, in this investigation, the mortar/rock interfaces are in most cases weaker than both mortars and rocks.


2015 ◽  
Vol 789-790 ◽  
pp. 38-42
Author(s):  
Nuria S. Mohammed ◽  
Ahmed Baharuddin Abd Rahman ◽  
Nur Hafizah A. Khalid ◽  
Musaab Ahmed

Polymer resin grout can be used as bonding material for grouted sleeve connections This paper presents the experimental results on the effectiveness of fly ash as micro filler to the splitting tensile strength of polymer grout. In addition, the cement grout that is usually used as bonding material had been tested for comparison. Eleven proportions, of fly ash as the filler and polymer as binder, were tested with the binder to filler volume ratios of 1:1 and 1:1.5. The test results revealed that fly ash can be used as a micro-filler material to partially replace ordinary river sand in polymer resin grout. The splitting tensile strength of the polymer grout increases with the increase of fly ash contents. However, for higher level of fly ash of more than 22%, the splitting tensile strength deteriorated. For binder: filler ratio of 1:1, the optimum fly ash content of 22% gave the maximum splitting strength of 17.62 MPa, which can be considered acceptable for producing grout with high strength bonding material.


2021 ◽  
Vol 30 (3) ◽  
pp. 464-476
Author(s):  
Haider Owaid ◽  
Haider Al-Baghdadi ◽  
Muna Al-Rubaye

Large quantities of paper and wood waste are generated every day, the disposal of these waste products is a problem because it requires huge space for their disposal. The possibility of using these wastes can mitigate the environmental problems related to them. This study presents an investigation on the feasibility of inclusion of waste paper ash (WPA) or wood ash (WA) as replacement materials for fly ash (FA) class F in preparation geopolymer concrete (GC). The developed geopolymer concretes for this study were prepared at replacement ratios of FA by WPA or WA of 25, 50, 75 and 100% in addition to a control mix containing 100% of FA. Sodium hydroxide (NaOH) solutions and sodium silicate (Na2SiO3) are used as alkaline activators with 1M and 10M of sodium hydroxide solution.The geopolymer concretes have been evaluated with respect to the workability, the compressive strength, splitting tensile strength and flexural strength. The results indicated that there were no significant differences in the workability of the control GC mix and the developed GC mixes incorporating WPA or WA. Also, the results showed that, by incorporating of 25–50% PWA or 25% WA, the mechanical properties (compressive strength, splitting tensile strength and flexural strength) of GC mixes slightly decreased. While replacement with 75–100% WPA or with 50–100% WA has reduced these mechanical properties of GC mixes. As a result, there is a feasibility of partial replacement of FA by up to 50% WPA or 25% WA in preparation of the geopolymer concrete.


Author(s):  
Hafez Elsayed Elyamany ◽  
Abd Elmoaty Mohamed Abd Elmoaty ◽  
Abdul Rahman Ahmed Diab

This research focused on the role of fly ash and silica fume on slag geopolymer concrete through investigating workability (slump, and slump loss), initial setting time, final setting time, and mechanical properties of slag geopolymer concrete, S-GPC, (compressive strength, splitting tensile strength, modulus of elasticity) in addition to SEM (Scanning electron microscope), and X-Ray analysis. The considered variables included, fly ash (FA) content as a replacement of ground granulated blast furnace slag (GS) (0, 10, 20, 30, and 40 %), presence of silica fume (SF) as a replacement of slag, concentration of sodium hydroxide, NaOH, (molarity: 10M, 16M, and 18M), additional water content (7.5,11,14, and 20 %), and curing type (thermal, air, and water curing). S-GPC yielded rapid stiffening and high slump loss with high mechanical properties. The use of silica fume or fly ash or a mix of them enhanced workability, decreased rate of slump loss, and delayed setting time. ACI 318 equation over estimates splitting tensile strength of FS-GPC.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Xue-lei Duan ◽  
Jing-shuang Zhang

In order to investigate the effects of fly ash and polypropylene fiber on mechanical properties, failure mode, and microstructure of soil-cement, the unconfined compression test, splitting tension test, and scanning electron microscopy (SEM) test of soil-cement with different polypropylene fiber contents (0%, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% by weight of dry soil) and fly ash contents (0%, 4%, 8%, and 12% by weight of dry soil) were carried out. The compressive and tensile strengths, deformation characteristics, failure mode, and microstructure of soil-cement modified with fly ash and polypropylene fiber were analyzed. The results show that the unconfined compressive strength and splitting tensile strength of soil-cement show a trend of increasing first and then decreasing with the increase of polypropylene fiber and fly ash content. Under the condition of 0.4% polypropylene fiber and 8% fly ash, the unconfined compressive strength and the splitting tensile strength are 4.90 MPa and 0.91 MPa, respectively, which increased by 32.79% and 51.67% as compared with the plain soil-cement, respectively. When 8% fly ash was used in the experiment, the unconfined compressive peak strain and the splitting tensile peak strain of the inclusion of 0.4% polypropylene fiber were 0.0410 and 0.0196, respectively. The corresponding peak strains were increased by 20.94% and 68.97% as compared with non-fiber-stabilized soil-cement, respectively. The stress-strain curve of fly ash soil-cement modified with polypropylene fiber can be divided into compaction phase, linear rise phase, nonlinear rise phase, and failure phase. Polypropylene fiber constrains the lateral deformation of fly ash soil-cement, which improves the peak strain and the failure mode of soil-cement.


Author(s):  
H. Tian ◽  
Y. X. Zhang

In this paper, a new green hybrid bagasse fiber (3% by volume) and steel fiber (0.7% by volume) reinforced cementitious composites with high volume fly ash (fly ash to cement ratio of 1.6) is developed and cured in weather condition up to 10 months. Basic mechanical tests, such as compressive test, Young’s modulus test, flexural test, and uniaxial tensile test and SEM tests were conducted at the age of 28 days, 3 months, 6 months and 10 months, respectively. Through comparison with the mechanical behavior of the composite at the age of 28 days, the long-term effect on the mechanical properties of the composite is evaluated. It is found the mechanical properties of the new composite increases greatly with aging. At the age of 10 months, the composite becomes more compacted and the composite is of excellent mechanical properties making it very promising to be used as commercial building materials.


2020 ◽  
Vol 897 ◽  
pp. 78-84 ◽  
Author(s):  
Sallal R. Abid ◽  
Ali N. Hilo ◽  
Yasir H. Daek ◽  
Nadheer S. Ayoob

This research aims to investigate the mechanical properties of engineered cementitious composites including compressive strength, splitting tensile strength, modulus of rupture, and load-deflection behavior. In addition, the abrasion test of concrete under water, which is recommended by ASTM C1138, was carried out and its results were compared with the splitting and modulus of rupture test results. Untreated low-cost polyvinyl fibers were used with different volume fractions of 0.5, 1.0, 1.5, and 2.0%. All tests were carried out at the standard age of 28 days. The experimental results showed that the use of 2% of low cost polyvinyl fibers with the engineered cementitious composites led to the increase of the splitting tensile strength and the modulus of rupture by 134% and 287%, respectively, compared to specimens incorporating no fibers. The results showed also that the deflection and the ultimate failure load increases as the fiber content increase.


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