Search Results/Filters    

Filters

Year

Banks




Expert Group











Full-Text


Author(s): 

ANSARI GH. | MOGHASSEM K.

Issue Info: 
  • Year: 

    2003
  • Volume: 

    20
  • Issue: 

    4
  • Pages: 

    568-576
Measures: 
  • Citations: 

    0
  • Views: 

    1608
  • Downloads: 

    0
Keywords: 
Abstract: 

Background and Aim: ZOE has been used in different fields of dentistry for many years. A locally produced component (Zoliran) has been recently introduced to the marketwith similar characteristic to the original Zonalin. Because of a lower cost involved to use Zoliran cement and its availability, confirm reliability of its physical properties. This investigation was designed to assess the Compressive Strength of Zoliran cement in comparison to Zonalin cement as the standard material. Materials and Methods: Five samples with dimension of 4mmx6mm of each cement were provided and stored in distilled water in 370C±10C for a period of 24 hours. The lowest load of force was registered as the reference to which the sample could be broken by(according to the criteria No: 30 of ANSIIADA). The value of Compressive Strength was then calculated using the following formula (K =4F/πD2 ). Results: The mean Compressive Strength of five samples was measuredas: 14.33 Mpa for Zoliran cement and 31.83 Mpa for Zonalin cement. The mean Compressive Strength of Zonalincement was significantly higher than the mean suggested in ANSl/ADA Specification No.30. The mean CompressiveStrength of Zoliran cement was also lower than the mean value registered in ANSI/ADA SpecificationNo.30. Conclusion: Compressive Strength of Zoliran cement was significantlylower than that of Zonalin cement. Further tests are required to compare the other physical properties of this material before it can be clinically recommended.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 1608

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Journal: 

ENGINEERING GEOLOGY

Issue Info: 
  • Year: 

    2022
  • Volume: 

    15
  • Issue: 

    1
  • Pages: 

    105-118
Measures: 
  • Citations: 

    0
  • Views: 

    133
  • Downloads: 

    14
Abstract: 

Strength measurement of rock requires testing that must be carried out on test specimens with particular sizes in order to fulfill testing standards or suggested methods. Often, the coring process breaks up the weaker core pieces, and they are too small to be used in either index tests or conventional Strength tests such as point load index (Is) and Brazilian tensile Strength (BTS). One of the index tests to indirectly determine the rock Strength is the block punch index (BPI) test, which requires flat disc specimens without special treatment. This study aimed to evaluate the applicability of the BPI test for predicting the uniaxial Compressive Strength (UCS), BTS and IS of the sandstones by empirical equations. Also, we have compared the performance of the BPI and IS for predicting the UCS and BTS. It was experimentally shown that BPI is a reliable method for predicting the UCS, BTS and Is of the sandstones under study. Moreover, the results indicate that BPI could be utilized with same importance as Is for predicting the UCS, while predicting the BTS by Is appears to be more reliable than BPI.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 133

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 14 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Author(s): 

RAO C.B.K. | SUDHAKAR M.

Issue Info: 
  • Year: 

    1990
  • Volume: 

    -
  • Issue: 

    -
  • Pages: 

    0-0
Measures: 
  • Citations: 

    1
  • Views: 

    158
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 158

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 1 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2005
  • Volume: 

    19
  • Issue: 

    4
  • Pages: 

    272-277
Measures: 
  • Citations: 

    1
  • Views: 

    101
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 101

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 1 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2008
  • Volume: 

    37
  • Issue: 

    3 (55) CIVIL ENGINEERING
  • Pages: 

    57-68
Measures: 
  • Citations: 

    0
  • Views: 

    272
  • Downloads: 

    0
Abstract: 

Researches show that concretes containing 25 to 35 % slag powder (as alternation for Protland cement) obtain Compressive Strength CS about 85% and 97% of the control specimens (without slag) at the ages of 28 and 90 days respectively. These concretes, also, recorded less growth rate of the CS than the control specimen at early ages (<28 days). In order to increase the early CS of these concretes and acquire 28-daysold CS about control specimens, this investigation was carried out using various percentage of the silica fume replaced with known quantities of Prortland cement. The results revealed that specimens containing 5% silica fume along with 25 to 35% slag powder displayed 5.2% and 13.3% higher than CS of control specimens at the 28 and 90 days respectively. In other part of the study the CS of the concretes containing slag powder cured with water comprising 2.5% MgSo4 as well as 2.5% NaCl were evaluated. Slag-contained specimens, which were placed in above mentioned curing situation, showed less CS at 28 days than control specimens whereas at the age of 90 and 180 days CS of the specimens were higher than the control specimence. The 25% slag-contained speciemens placed in sulphated situation at 180 day old stage showed 325 Kglcm2 CS which was 14.44% higher than the control sample attaining the best result. here with material and geometric nonlinear analysis. In this paper, buckling behavior and ultimate capacity of built up castellated compound columns are investigated using ANSYS software. A brief of results is reported on for a number of CPE sections in different boundary conditions. Also is presented slenderness-load curve by using of Jandel software, which is a useful tool for investigation of ultimate capacity of the columns.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 272

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2023
  • Volume: 

    53
  • Issue: 

    3
  • Pages: 

    192-205
Measures: 
  • Citations: 

    0
  • Views: 

    139
  • Downloads: 

    23
Abstract: 

Brick is the most widely used construction material. Demolition of buildings and production of construction waste, including clay brick, are dramatically increasing in an alarming rate. The production of traditional bricks such as clay bricks has hazardous impacts on the environment, such as pollution and extensive use of natural resources. This study addressed the application of the geo-polymerization process as an environmental and sustainable method to produce new bricks from clay brick waste and different types of fillers. Accordingly, the powder and grains of clay brick waste, dune sand, washed sand, industrial sodium hydroxide, and water glass were utilized to prepare cubic and brick-shaped geopolymer samples with different mix designs and then cured at 70 °C. The samples' Compressive Strength, water absorption and SEM analysis were examined. According to the results, the highest Compressive Strength for cubic mortar samples was obtained in the case without filler; for these samples, with mass ratios of water glass to sodium hydroxide solution equal to 1 and 2, Compressive Strength was 18.45 and 22.15 MPa, respectively. In the brick samples, the highest Compressive Strength was obtained in the 28-day and 8 M geopolymer samples, which was equal to 25.38 MPa. On the other hand, the geopolymer samples made by sand filler had higher Compressive Strength and lower water absorption in comparison to other samples. Therefore, sustainable production of geopolymer bricks from clay brick waste and inexpensive materials as the filler can be a step toward mitigating the environmental impact of construction and demolition waste.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 139

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 23 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Author(s): 

Fatahi O. | JAFARI S.

Issue Info: 
  • Year: 

    2018
  • Volume: 

    6
  • Issue: 

    2
  • Pages: 

    154-163
Measures: 
  • Citations: 

    0
  • Views: 

    166
  • Downloads: 

    69
Abstract: 

Nowadays, the better performance of lightweight structures during earthquake has resulted in using lightweight concrete more than ever. However, determining the Compressive Strength of concrete used in these structures during their service through a none-destructive test is a popular and useful method. One of the most original approach of non-destructive testing to obtain of Compressive Strength of concrete used in structures is ultrasonic pulse velocity test. The purpose of this research is predicting the Compressive Strength of LWA concrete by proposing an accurate mathematical formulation. Many samples of lightweight aggregate concrete, made by expanded clay, have been produced and tested. After determining the actual Compressive Strength and indirect ultrasonic pulse velocity for each sample, a relationship was derived to estimate the Compressive Strength through Gene Expression Programming (GEP). The results show the presented equation shows high accuracy in predicting the Compressive Strength of LWA and the estimated outcomes have a considerable compatibility with actual samples.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 166

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 69 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2017
  • Volume: 

    50
  • Issue: 

    2
  • Pages: 

    207-219
Measures: 
  • Citations: 

    0
  • Views: 

    250
  • Downloads: 

    143
Abstract: 

This study introduces, two models based on Gene Expression Programming (GEP) to predict Compressive Strength of high Strength concrete (HSC). Composition of HSC was assumed simplified, as a mixture of six components (cement, silica fume, super-plastisizer, water, fine aggregate and coarse aggregate). The 28-day Compressive Strength value was considered the target of the prediction. Data on 159 mixes were taken from various publications. The system was trained based on 80% training pairs chosen randomly from the data set and then tested using remaining 20% samples. Therefore it can be proven and illustrated that the GEP is a strong technique for the prediction of Compressive Strength amounts of HSC concerning to the outcomes of the training and testing phases compared with experimental outcomes illustrate that the.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 250

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 143 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Author(s): 

AKHAVAN ZANJANI VAGHAREDIN | SHEIKH AL ESLAMIAN SEYEDEH MAHSA | TABARI KASRA

Issue Info: 
  • Year: 

    2016
  • Volume: 

    34
  • Issue: 

    3
  • Pages: 

    129-136
Measures: 
  • Citations: 

    0
  • Views: 

    393
  • Downloads: 

    132
Abstract: 

Objectives: Maintaining pulp vitality is a main goal in restorative dentistry. Introduction of pulp capping agents paved the way to eliminate the shortcomings of these materials and obtain successful restorations. On the other hand, nanotechnology is an emerging field of science with increasing use in dental materials. This study sought to assess the effect of addition of nano-TiO2, nano-SiO2 and nano-Al2O3 on Compressive Strength of five hydraulic cements.Methods: In this in vitro, experimental study, three experimental formulations of nano hybrid MTA, MTA Angelus and MTA Angelus+nano-oxide particles cements were placed in molds measuring 4±0.1mm in internal diameter and 6±0.1mm in height made of stainless steel (ISO9917-1). Ten samples were fabricated for each of the five groups of materials. Sound samples were stored at 37oC and 95±5% humidity and were subjected to Compressive Strength testing in a universal testing machine at a crosshead speed of 0.5mm/minute after 24 hours and one month. Two-way ANOVA, one-way ANOVA and independent samples t-test were used for comparison of Compressive Strength of groups at different time points.Results: The highest Compressive Strength belonged to MTA Angelus+nanohydroxyapatite and nano-hybrid MTA C at 24 hours and 30 days, respectively. The lowest Compressive Strength belonged to nano-hybrid MTA B and MTA Angelus at 24 hours and 30 days, respectively (P<0.05).Conclusion: Addition of nanoparticles affected the Compressive Strength of cements. Compressive Strength significantly increased over time in all groups.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 393

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 132 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Author(s): 

Aminbakhsh Sina | Tohidi Amin

Issue Info: 
  • Year: 

    2024
  • Volume: 

    1
  • Issue: 

    1
  • Pages: 

    1-7
Measures: 
  • Citations: 

    0
  • Views: 

    1
  • Downloads: 

    0
Abstract: 

Accurate prediction of the uniaxial Compressive Strength (UCS) of concrete is crucial for ensuring the safety, durability, and performance of structures in construction. This study presents a predictive model using a multilayer perceptron (MLP), to estimate UCS based on key input parameters such as water-cement ratio, aggregate size, curing time, water and cement content. The MLP model was trained and validated using a dataset comprising 120 cubic laboratory-tested concrete samples (15cm × 15cm × 15cm) with varying compositions for normal construction materials. Performance of the model was evaluated using statistical metrics (split into training and testing sets as 70%-30%), showing that the MLP-based approach provides accurate and reliable predictions compared to traditional regression models. The proposed method offers a practical, efficient tool for geotechnical engineers to assess concrete Strength, potentially reducing the need for extensive experimental testing and enhancing quality control in concrete production.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 1

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
litScript
telegram sharing button
whatsapp sharing button
linkedin sharing button
twitter sharing button
email sharing button
email sharing button
email sharing button
sharethis sharing button