scholarly journals Effects of Soluble Lignocellulose Substances of Wood Particles on the Mechanical Properties of Lightweight Concrete

2018 ◽  
Vol 7 (4.20) ◽  
pp. 377
Author(s):  
Aqil M. ALmusawi ◽  
Zaid A. ALzaidi ◽  
Tamara A. Qasim
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Lightweight Concrete ◽  
Setting Time ◽  
Treated Wood ◽  
Boiling Water ◽  
Initial Setting Time ◽  
Mix Proportion ◽  
Wood Particles ◽  
Initial Setting

Recent trends in lightweight concrete manufacturing have led to a proliferation of studies demonstrating that wood aggregates can be used to produce sustainable green concrete composites. However, wood particles contain soluble substances (saccharides), which have a significant effect on the setting time of Portland cement. To attain a better understanding of this, two types of wood were treated in boiling water. After the treatment process, the resulting water (“boiling water of wood”) was used to study its effect on the initial setting time of Portland cement. The mechanical properties and the density were also investigated for concrete mixtures consisting of 0, 5, 7.5, and 10% treated wood particles (weight replacement from coarse aggregate). As a result, the effect of the wood’s soluble substances was determined and the optimum mix proportion was chosen for achieving the minimum nominal density and the best mechanical properties.  

Properties of slag geopolymer concrete modified with fly ash and silica fume

2021 ◽  
Author(s):  
Hafez Elsayed Elyamany ◽  
Abd Elmoaty Mohamed Abd Elmoaty ◽  
Abdul Rahman Ahmed Diab
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Setting Time ◽  
Splitting Tensile Strength ◽  
Geopolymer Concrete ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Additional Water

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.

scholarly journals Compressive Strength and Setting Time of MTA and Portland Cement Associated with Different Radiopacifying Agents

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Mario Tanomaru-Filho ◽  
Vanessa Morales ◽  
Guilherme F. da Silva ◽  
Roberta Bosso ◽  
José M. S. N. Reis ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Zirconium Oxide ◽  
Setting Time ◽  
Strontium Carbonate ◽  
Strength Test ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Compressive Strength Test ◽  
Initial Setting

Objective. The aim of this study was to evaluate the compressive strength and setting time of MTA and Portland cement (PC) associated with bismuth oxide (BO), zirconium oxide (ZO), calcium tungstate (CT), and strontium carbonate (SC). Methods. For the compressive strength test, specimens were evaluated in an EMIC DL 2000 apparatus at 0.5 mm/min speed. For evaluation of setting time, each material was analyzed using Gilmore-type needles. The statistical analysis was performed with ANOVA and the Tukey tests, at 5% significance. Results. After 24 hours, the highest values were found for PC and PC + ZO. At 21 days, PC + BO showed the lowest compressive strength among all the groups. The initial setting time was greater for PC. The final setting time was greater for PC and PC + CT, and MTA had the lowest among the evaluated materials (P<0.05). Conclusion. The results showed that all radiopacifying agents tested may potentially be used in association with PC to replace BO.

An Accurate and Quick Measuring Method for Mix Proportion of Concrete Paste in Construction Site

2010 ◽  
Vol 450 ◽  
pp. 482-485
Author(s):  
Li Peng Cai ◽  
Ii Young Jang ◽  
Ying Wei Yun ◽  
Seong Kyum Kim
Keyword(s):  
Setting Time ◽  
Measuring Method ◽  
In Situ Monitoring ◽  
Construction Site ◽  
Monitoring Method ◽  
Initial Setting Time ◽  
Mix Proportion ◽  
Initial Setting

An effective in-situ monitoring method for MPCP is urgently needed in civil engineering field. In this research, a quick and accurate in-situ measuring method for mix proportion of concrete is put forward. This method can succeed in measuring real mix proportion of any concrete paste precisely within 20 minutes according to four parameters of concrete before initial setting time of concrete. By comparing the designed mix proportion of concrete with the real measured one in construction site by this method, the quality of concrete can be demonstrated. This method can evaluate the reliability of mix proportion for real concrete in construction site quickly and precisely, and ensure the quality of concrete structures to avoid the occurrence of engineering accidents.

The Influence of Alcohol Amine Admixtures on the Macroscopic Properties of Portland Cement Paste

2014 ◽  
Vol 525 ◽  
pp. 573-579
Author(s):  
Tian Yong Huang ◽  
Dong Min Wang ◽  
Ze Liu
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Cement Paste ◽  
Setting Time ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Cement Mortars ◽  
Macroscopic Properties ◽  
Initial Setting

It is studied the influence of triethanolamine (TEA), diethylenetriamine (DEA), Triisopropanolamine (TIPA), aminoethyl ethanolamine (AE), and polyvinyl alcohol ammonium phosphate (PAAP) at different dosages on the properties of fresh and hardened cement pastes and mortars prepared by Portland cement, including standard consistency water, setting time, the cement paste fluidity, and compressive and flexural strength. It is showed that the high polarity alcohol amine molecules exhibit strong chemical interactions with cement matrix, which are reflected in modified macroscopic properties of the cement system. All alcohol amine admixtures increased the standard consistency water and decreased cement paste fluidity of Portland cement. TEA significantly shortened the initial setting time and final setting time of Portland cement. On the other hand, TIPA, DEA, AE and PAAP extended the initial setting time of cement but shortened the cement final setting time. All alcohol amine admixtures except TIPA at 0.2 and 0.5 dosage increased the compressive and flexural strength of the Portland cement mortars at 3 days. Especially when the dosage of PAAP is 1, the compressive strength of the Portland cement mortars at 3 days is increased 10.5MPa. All alcohol amine admixtures except AE at 0.2 and 0.5 dosage increase the compressive and flexural strength of the Portland cement mortars at 28 days, Especially when the dosage of TIPA is 1, the compressive strength of the Portland cement mortars at 28 days is increased 8.8MPa.

Influence of Testing Methods on Setting Time of Foam Concrete

2010 ◽  
Vol 177 ◽  
pp. 514-517
Author(s):  
Xin Gang Yu ◽  
Yu Rong Wei ◽  
Shi Song Luo ◽  
Kang Yan Zeng ◽  
De Jun Li ◽  
...  
Keyword(s):  
Portland Cement ◽  
Building Materials ◽  
Setting Time ◽  
Functional Materials ◽  
Mineral Admixture ◽  
Future Market ◽  
Foam Concrete ◽  
Prefer Method ◽  
Initial Setting Time ◽  
Initial Setting

As a porous material, foam concrete can be manufactured not only into building materials with good heat insulation performance, but also into materials with good water permeability, and by properly controlling the size and shape of the pores, the foam concrete can be used as acoustic material to meet People's increasing demand for functional materials. Therefore, the development of foam concrete has a vast potential for future market. Though the setting time of foam concrete is one of the key technical parameters for the preparation of high performance foam concrete, there is no standard method for the testing of the foam concrete’s setting time. That militates against the development of foam concrete greatly. In this paper, two methods were used to measure the setting time of foam concrete. The results show that the offset value of the foam concrete’s initial setting time measured by the two different methods increases with the increasing of foam volume adding to the foam concrete which use the Portland cement and Portland cement-mineral admixture as binder. Finally, a prefer method to test the foam concrete’s initial setting time was selected.

scholarly journals SUBTITUSI SAMPAH ORGANIK DAN TANAH MEDITERAN MENJADI SEMEN ALTERNATIF SELAIN SEMEN PORTLAND

2018 ◽  
Vol 7 (2) ◽  
pp. 119
Author(s):  
Muhammad Syarif ◽  
Victor Sampebulu ◽  
Muh. Wihardi Tjaronge ◽  
Nasruddin Junus
Keyword(s):  
Portland Cement ◽  
Chemical Compound ◽  
Setting Time ◽  
Bottom Ash ◽  
Test Methods ◽  
Household Waste ◽  
Coal Waste ◽  
Initial Setting Time ◽  
Alternative Materials ◽  
Initial Setting

The results of this study aims to save the environment, through the discovery of new alternative materials by recycling organic waste, household waste, coal waste (fly ash and bottom ash), and substitution of mediteran land and clay into organic cement that is alternative cement in addition portland cement. Test results of organic cement chemical compound using laboratory testing method refers to ASTM C-114 and SNI 15-2049-2004. An indication of resembling a portland cement chemical compound is CaO of 65.36%, SiO₂ 18.84%, AlOO₃ 6.33%, Fe₂O₃ 2.29%, SO₃ 3.64%, MgO 1.35%, C₃S 66 , 72%, C₂S 3.98%, C₃A 12.9%, and C4Af 6.97%. Test methods of physical properties include testing of baseline time and end time and normal consistency value to organic cement, this test refers to ASTM C 191-04 and C 191-08 and ASTM C 187-04. Fineness of organic cement grains that passed in the mesh 200 mesh as much as 56%, more subtle than portland cement is 52%. The solid weight of organic cement is 1200 kg/m3, lighter than portland cement which reaches 1250 kg/m3. The initial setting time for organic cement was 105 minutes, longer than portland cement at 90 minutes. For the organic cement final time at 225 minutes, it was above the end time of portland cement at 180 minutes.

scholarly journals Experimental Study on Mechanical Properties of Repair Materials for Underwater Rapid Construction

2022 ◽  
Vol 2148 (1) ◽  
pp. 012062
Author(s):  
Shangchuan Zhao ◽  
Longlong Liu ◽  
Xindai Zuo ◽  
Shaopeng Wang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Setting Time ◽  
Cement Concrete ◽  
Initial Setting Time ◽  
Sulphoaluminate Cement ◽  
Final Setting Time ◽  
Rapid Construction ◽  
Repair Materials ◽  
Initial Setting

Abstract Several strength grades of sulphoaluminate cement concrete were designed, and the mechanical properties with different mix ratios were studied. This paper mainly analyzes the mechanical properties of sulphoaluminate cement concrete with the setting time test, compressive strength test and flexural test. The test results show that the setting time of cement concrete can be controlled by mixing different admixtures. One hand, the initial setting time increases from 34 min to 340 min, and the final setting time increases from 57 min to 580 min when the incorporated borax content changes from 0 to 1.0 %. Other hand, the initial setting time decreased from 34 min to 11 min, and the final setting time increased from 57 min to 18 min, when the incorporated borax content changed from 0 to 0.5 %. Furthermore, the compressive strength can reach 40 MPa, and the flexural strength can reach more than 2.5MPa after 6 hours of curing. The experiment results illustrate that the setting time and the mechanical properties satisfy the needs of the rapid construction requirements under normal temperature conditions.

scholarly journals Effect of poly(ethylene glycol) on the injectability, setting behavior and mechanical properties of calcium phosphate bone cement

2018 ◽  
Vol 19 (2) ◽  
pp. 192-202
Author(s):  
Sufiamie Hablee ◽  
IIS SOPYAN ◽  
Maizirwan Mel ◽  
Hamzah Mohd. Salleh ◽  
Md. Mujibur Rahman
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Calcium Phosphate ◽  
Ethylene Glycol ◽  
Setting Time ◽  
Poly Ethylene Glycol ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Initial Setting ◽  
Poly Ethylene

ABSTRACT: The present paper reports on the effect of poly(ethylene glycol) (PEG) addition on injectability, setting behaviour, and mechanical properties of calcium phosphate cement (CPC) for injectable bone filling applications. Calcium hydroxide, Ca(OH)2, and diammonium hydrogen phosphate, (NH4)2HPO4, have been used as precursors in wet chemical precipitation synthesis of hydroxyapatite powder. Cement paste was prepared with different powder-to-liquid ratios, varied at 1.0, 1.3, 1.5 and 2.0. The incorporation of PEG was also varied at 1, 2, 3, 4 and 5 wt% at the powder-to-liquid ratio of 1.3. The CPC produced was then evaluated in terms of injectability, setting time and mechanical strength. The results indicated that PEG addition significantly improved setting time, injectability, as well as compressive strength of CPC. Without PEG, the initial setting time ranged between 3 and 122 min, while the final setting time ranged between 5 and 277 min. The addition of PEG has significantly improved setting time where the initial setting time ranged from 47 to 88 min and the final setting time ranged from 182 to 228 min. The extrusion load decreased when PEG was added, which revealed an improvement in injectability; 82.5% without PEG addition and 95.5% when 5% PEG was added. The compressive strength of CPC is in the range of 0.59 to 1.344 MPa and its porosity is in the range of 39.2% to 47.1%. With the incorporation of PEG, the compressive strength greatly increased to the range of 1.167 and 1.786 MPa.. ABSTRAK: Penyelidikan ini melaporkan tentang kesan menambah polietilina glikol (PEG) terhadap sifat-sifat simen kalsium fosfat seperti keupayaan suntikan, masa pengerasan dan kekuatan mekanikal. Kalsium hidroksida dan diammonium hidrogen fosfat digunakan sebagai reagen dalam kaedah pemendakan kimia basah bagi menghasilkan serbuk hidroksiapatit. Pes simen disediakan dengan nisbah serbuk kepada cecair yang berbeza, dengan nisbah 1.0, 1.3, 1.5 dan 2.0. Kemudian, PEG ditambah ke dalam simen kalsium fosfat dengan kepekatan yang berbeza, bernilai 1, 2, 3, 4 dan 5 wt% bagi 1.3 nisbah serbuk kepada cecair. Simen yang terhasil diuji bagi menilai keupayaan suntikan, masa pengerasan dan kekuatan mekanikal. Keputusan ujian-ujian tersebut menunjukkan bahawa penambahan PEG ke dalam simen telah meningkatkan kebolehan simen untuk disuntik, mengurangkan masa pengerasan simen dan meningkatkan kekuatan mekanikal simen. Simen tanpa PEG mempunyai masa pengerasan awal daripada 3 min kepada 122 min dan masa pengerasan akhir daripada 5 min kepada 277 min. Apabila PEG ditambah, masa pengerasan simen menjadi lebih baik dengan masa pengerasan awal daripada 47 min kepada 88 min dan masa pengerasan akhir daripada 182 min kepada 228 min. Peningkatan dalam keupayaan simen untuk disuntik telah dibuktikan dengan pengurangan beban penyempitan apabila PEG ditambah ke dalam simen. Simen tanpa PEG mempunyai 82.5% keupayaan suntikan dan meningkat kepada 95.5% apabila 5% PEG ditambah. Kekuatan mampatan simen bernilai antara 0.59 dan 1.334 MPa dan keliangan simen bernilai antara 39.2% dan 47.1%. Kekuatan mampatan simen meningkat dengan ketara apabila PEG ditambah, bernilai antara 1.167 dan 1.786 Mpa.

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