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.

Environmental Friendly Sulphoaluminate Cement Based Rapid Hardening and Repair Materials

2014 ◽  
Vol 548-549 ◽  
pp. 12-15 ◽  
Author(s):  
Meng Jie Lu ◽  
Ming Fang Ba ◽  
Dan Yi Man ◽  
Si Yuan Ma ◽  
Jie Yang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Setting Time ◽  
Mass Ratio ◽  
Rapid Hardening ◽  
Initial Setting Time ◽  
Sulphoaluminate Cement ◽  
Repair Materials ◽  
Initial Setting ◽  
Working Performance

In order to save the costs of the rapid hardening and repair sulphoaluminate cement and improve its working performance, the effects of slag, fly ash, silica fume in different contents and different adding ways on the initial setting time and working performance of sulphoaluminate cement are studied. The results show that the initial setting time of single-doped slag and fly ash both meet the requirements of repair materials, but silica fume significantly cuts the cement’s initial setting time short, which does not meet the construction conditions for rapid hardening and repair. Ultimately it is determined that the mechanical properties of sulphoaluminate cement are the best when slag and fly ash are compound added by the content of 30% at 4:1 mass ratio and simultaneously the initial setting time meets the conditions for rapid hardening and repair.

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.

scholarly journals Influence of Ultrafine Natural Steatite Powder on Setting Time and Strength Development of Cement

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
K. Sudalaimani ◽  
M. Shanmugasundaram
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
Element Distribution ◽  
Strength Development ◽  
X Ray Diffraction ◽  
Dormant Period ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Initial Setting ◽  
Cement Binder

This paper deals with the setting time and pozzolanic activity of cement when ultra fine natural steatite powder (UFNSP) is used as replacement for cement. Initial setting time, final setting time, and mortar cube strength were studied, due to the replacement of ultra fine natural steatite powder with cement at 5%, 10%, 15%, 20%, and 25% by mass of cement. The setting time of fresh cement-binder paste and compressive strength of mortar cubes are observed. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were applied to investigate the microstructural behaviour and chemical element distribution inside cement-binder matrix. Results indicate that the length of dormant period is shortened. The replacement of ultra fine natural steatite powder with cement reduces initial setting time, and final setting time and increases mortar cube compressive strength.

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 Triethanolamine on the Properties of Cement-Based Materials

2017 ◽  
Vol 898 ◽  
pp. 2010-2017 ◽  
Author(s):  
Xiao Ying Wang ◽  
Ming Zhang Lan ◽  
Wei Fang Hou ◽  
Bin Feng Xiang ◽  
Xu Dong Zhao
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Hydration ◽  
Setting Time ◽  
Cementitious Materials ◽  
Hydration Products ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Retarding Effect ◽  
Initial Setting

The effects of triethanolamine on the compressive strength and setting time of fly ash cementitious materials, slag cementitious materials, and limestone cementitious materials were investigated. The results show that the dosage of 0.04% of triethanolamine can significantly improve the 3d, 7d and 28d compressive strength of fly ash cementitious materials. It possesses less impact on the setting time. The dosage of 0.04% of triethanolamine can significantly improve the 3d and 7d compressive strength of slag cementitious materials while the effect of late strength is not obvious. It extends the initial setting time and the final setting time is not changed, which has retarding effect. The results of hydration heat and XRD show that triethanolamine extends the induction period of cement hydration, and gypsum is exhausted in advance during the hydration process. Triethanolamine promotes the transformation of AFt to AFm and there is no effect on the type of hydration products.

Study on the Properties of Ground Limestone-High Alumina Cement Gelation System

2011 ◽  
Vol 317-319 ◽  
pp. 489-497
Author(s):  
Jia Xiao ◽  
Cheng Fu Gou ◽  
Cai Yun Xu ◽  
Hao Xing ◽  
Yong Gang Jin
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
High Alumina ◽  
Alumina Cement ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
High Alumina Cement ◽  
Binder Ratio ◽  
Initial Setting ◽  
Ground Limestone

Effects of various amounts of ground limestone on the setting time, fluidity and compressive strength of high alumina cement were described in this paper. Microstructure analyses were performed by SEM. The results indicate that the initial setting time, the final setting time, the fluidity and the compressive strength of the pastes increase first and decrease later with the ground limestone content increasing, all of which reach the maximum when the ground limestone content is 3%. Meanwhile, an increase of the fineness of the ground limestone produces a shorter setting time, the fluidity of the pastes increases when the content of the ground limestone increases, and the compressive strength of the hardened pastes increases with the ground limestone content increasing and decreases with water-binder ratio increasing. The 28d strength of the pure high alumina cement paste is lower than the 3d strength, appearing the strength shrinkage, which can be improved by a proper addition of the ground limestone.

scholarly journals Effect of Calcium Nitrate on the Properties of Portland–Limestone Cement-Based Concrete Cured at Low Temperature

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1611
Author(s):  
Gintautas Skripkiūnas ◽  
Asta Kičaitė ◽  
Harald Justnes ◽  
Ina Pundienė
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Setting Time ◽  
Calcium Nitrate ◽  
Curing Temperature ◽  
Hardened Concrete ◽  
Cement Pastes ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Early Strength

The effect of calcium nitrate (CN) dosages from 0 to 3% (of cement mass) on the properties of fresh cement paste rheology and hardening processes and on the strength of hardened concrete with two types of limestone-blended composite cements (CEM II A-LL 42.5 R and 42.5 N) at different initial (two-day) curing temperatures (−10 °C to +20 °C) is presented. The rheology results showed that a CN dosage up to 1.5% works as a plasticizing admixture, while higher amounts demonstrate the effect of increasing viscosity. At higher CN content, the viscosity growth in normal early strength (N type) cement pastes is much slower than in high early strength (R type) cement pastes. For both cement-type pastes, shortening the initial and final setting times is more effective when using 3% at +5 °C and 0 °C. At these temperatures, the use of 3% CN reduces the initial setting time for high early strength paste by 7.4 and 5.4 times and for normal early strength cement paste by 3.5 and 3.4 times when compared to a CN-free cement paste. The most efficient use of CN is achieved at −5 °C for compressive strength enlargement; a 1% CN dosage ensures the compressive strength of samples at a −5 °C initial curing temperature, with high early strength cement exceeding 3.5 MPa but being less than the required 3.5 MPa in samples with normal early strength cement.

scholarly journals Aplikasi Response Surface Methodology pada Optimasi Penambahan Blast Furnace Slag Terhadap Waktu Pengikatan dan Kuat Tekan Semen

2020 ◽  
Vol 4 (1) ◽  
pp. 61
Author(s):  
Hardjono Hardjono ◽  
Cucuk Evi Lusiani ◽  
Agung Ari Wibowo ◽  
Mochammad Agung Indra Iswara
Keyword(s):  
Compressive Strength ◽  
Response Surface Methodology ◽  
Blast Furnace ◽  
Response Surface ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Central Composite ◽  
Furnace Slag

Produksi semen setengah jadi (clinker) membutuhkan energi yang tinggi sehingga menggunakan batu bara dalam jumlah besar. Hal ini menyebabkan biaya produksi dari pabrik semen juga tinggi. Kebutuhan energi yang besar untuk menghasilkan clinker tersebut dapat dikurangi dengan menambahan blast furnace slag sebagai campuran pembuatan semen. Campuran clinker dapat menghasilkan produk semen yang memiliki waktu pengikatan dan kuat tekan sesuai SNI. Pengaruh penambahan blast furnace slag sebagai campuran clinker terhadap waktu pengikatan dan kuat tekan semen dapat dioptimalkan dengan response surface methodology (RSM) menggunakan Central Composite Design (CCD). Optimasi dengan menggunakan RSM bertujuan untuk mengetahui kondisi optimum pada penambahan blast furnace slag dan clinker terhadap variabel respon berupa waktu pengikatan awal, waktu pengikatan akhir, dan kuat tekan. Hasil uji ANOVA dan analisis response surface menunjukkan bahwa penambahan blast furnace slag sebagai campuran dalam pembuatan semen memberikan pengaruh yang signifikan terhadap waktu pengikatan awal, waktu pengikatan akhir, dan kuat tekan. Penambahan 5% blast furnace slag dengan 92,5% clinker pada campuran clinker dan gypsum merupakan kondisi optimum yang memberikan pengaruh signifikan terhadap variabel respon.The production of clinker consumes high energy and causes high production cost of cement industry. It can be reduced by adding blast furnace slag as a mixture in cement production. The blast furnace slag - clinker mixture can produce cement with setting time and compressive strength according to SNI. The effect of the addition of blast furnace slag as a clinker mixture to the setting time and compressive strength of cement can be optimized by response surface methodology (RSM) using Central Composite Design (CCD). Optimization by using RSM aims to determine the optimum condition of the blast furnace slag – clinker mixture to the initial setting time, final setting time, and compressive strength. ANOVA test results and response surface analysis show that the addition of blast furnace slag into the cement mixture has a significant influence on the initial setting time, final setting time, and compressive strength. The addition of  5% blast furnace slag with  92.5% clinker in the mixture of clinker and gypsum is the optimum condition which gives a significant effect on the response variable.

scholarly journals Analysis of the Influence of Crystalline Admixtures at Early Age Performance of Cement-Based Mortar by Electrical Resistance Monitoring

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5705
Author(s):  
Rubén Beltrán Cobos ◽  
Fabiano Tavares Pinto ◽  
Mercedes Sánchez Moreno
Keyword(s):  
Compressive Strength ◽  
Thermogravimetric Analysis ◽  
Remote Monitoring ◽  
Electrical Resistance ◽  
Setting Time ◽  
Early Age ◽  
Resistance Monitoring ◽  
Initial Setting Time ◽  
Characterization Techniques ◽  
Initial Setting

Crystalline admixtures are employed for waterproofing concrete. This type of admixtures can affect the early age performance of cement-based mixes. The electrical resistance properties of cement have been related to the initial setting time and to the hydration development. This paper proposes a system for remote monitoring of the initial setting time and the first days of the hardening of cement-based mortars to evaluate the effect of the incorporation of crystalline admixtures. The electrical resistance results have been confirmed by other characterization techniques such as thermogravimetric analysis and compressive strength measurements. From the electrical resistance monitoring it has been observed that the incorporation of crystalline admixtures causes a delay in the initial setting time and hydration processes. The measurements also allow to evaluate the influence of the amount of admixture used; thus, being very useful as a tool to define the optimum admixture dosage to be used.

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