scholarly journals A Mini Review on Properties of Portland Cement Concrete with Geopolymer Materials as Partial or Entire Replacement

2021 ◽  
Vol 6 (2) ◽  
pp. 26
Author(s):  
Kong Fah Tee ◽  
Sayedali Mostofizadeh
Keyword(s):  
Portland Cement ◽  
Experimental Tests ◽  
Alkaline Solutions ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
The Past ◽  
Laboratory Results ◽  
Temperature Water ◽  
Chemical Materials ◽  
Significant Factors

The main aim of this paper is to review recent studies over the past 10 years investigating the influencing factors for improving the mechanical properties of concrete. This focuses on concrete comprising of pozzolanic materials, partially or entirely replacing ordinary Portland cement, in the concrete mixture. Firstly, the effectiveness of main factors such as temperature, water to solid (W/S) ratio, and alkaline solution ratio was briefly discussed. Next, the effects of significant factors such as different superplasticizer and alkaline solutions and combinative materials on the improvement of concrete workability were reviewed and compared. Eventually, other concrete properties such as water absorption and durability were discussed in the last section. After reviewing all types of concrete additives, including mineral or chemical materials, the influence of these admixtures under different laboratory conditions were highlighted to objectively evaluate the benefits of each factor. As a whole, the significant reasons of such experimental tests arising from the usage of these materials, in accordance with the laboratory results obtained from these investigations, are discussed.

Thermogravimetric Analysis of Limestone Aggregates for Portland Cement Concrete

1998 ◽  
Vol 1619 (1) ◽  
pp. 37-44
Author(s):  
Stephen A. Cross ◽  
Mohamed Nagib Abou-Zeid
Keyword(s):  
Weight Loss ◽  
Thermogravimetric Analysis ◽  
Portland Cement ◽  
Coarse Aggregate ◽  
Pavement Performance ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
The Past ◽  
Good Potential ◽  
Durability Assessment

Durability of coarse aggregate has a major impact on the durability of portland cement concrete. Over the past years, there has been an increasing interest in developing and improving test techniques that provide a more accurate durability assessment, which ultimately leads to a better prediction of pavement performance. Thermogravimetric analysis is a relatively rapid technique that has shown good potential for use in the analysis of carbonate aggregates. Thermogravimetric technique (TG) was used to analyze 31 limestone aggregates. The specimens were heated to temperatures above 1000°C using two rates of temperature increase. The weight loss and the change in weight loss as a function of temperature were recorded. Results show a correlation between the slope before calcite transition and some durability aspects of limestone. Moreover, the TG output can be used to calculate the percent acid insoluble (AI) and the pavement vulnerability factor (PVF). Therefore, TG may be considered as a rapid method for AI and PVF determination.

scholarly journals Influence of Crumb-Rubber in the Mechanical Response of Modified Portland Cement Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
J. Retama ◽  
A. G. Ayala
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Damage Evolution ◽  
Mechanical Response ◽  
Numerical Models ◽  
Experimental Tests ◽  
Crumb Rubber ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Main Hypothesis

The influence of crumb-rubber on the mechanical properties of Portland cement concrete (PCC) is studied by experimental tests and numerical simulations. The main hypothesis of the study is that replacing part of the stone aggregate with crumb-rubber in the mix modifies the energy dissipation during the cracking process and affects the concrete behaviour under monotonically increasing loads. The experimental research program characterizes the mechanical properties of PCC for three different types of concrete with a variable content of crumb-rubber. The experimental results showed that fracture energy and other properties are directly related to the rubber fineness used in the mixture. The material properties derived for these laboratory tests are used to study, by numerical models, its response through its damage evolution. The numerical model used to simulate the damage evolution of the concrete is the Embedded Discontinuity Method (EDM). One characteristic of the EDM is that it does not need to modify the mesh topology to propagate the damage through the continuum solid. For this study, the Disk-Shaped Compact Tension specimen geometry, normed by the D7313-13 of the ASTM, is used. Results showed that the numerical methods provide good approximation of the experimental curve in the elastic and softening branches.

Development of a Capacitor Probe to Detect Subsurface Deterioration in Concrete

1997 ◽  
Vol 503 ◽  
Author(s):  
B. K. Diefenderfer ◽  
I. L. Al-Qadi ◽  
J. J. Yoho ◽  
S. M. Riad ◽  
A. Loulizi
Keyword(s):  
Dielectric Constant ◽  
Portland Cement ◽  
Electromagnetic Waves ◽  
Low Cost ◽  
Complex Dielectric Constant ◽  
Life Cycle Costs ◽  
Parallel Plates ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Set Up

ABSTRACTPortland cement concrete (PCC) structures deteriorate with age and need to be maintained or replaced. Early detection of deterioration in PCC (e.g., alkali-silica reaction, freeze/thaw damage, or chloride presence) can lead to significant reductions in maintenance costs. However, it is often too late to perform low-cost preventative maintenance by the time deterioration becomes evident. By developing techniques that would enable civil engineers to evaluate PCC structures and detect deterioration at early stages (without causing further damage), optimization of life-cycle costs of the constructed facility and minimization of disturbance to the facility users can be achieved.Nondestructive evaluation (NDE) methods are potentially one of the most useful techniques ever developed for assessing constructed facilities. They are noninvasive and can be performed rapidly. Portland cement concrete can be nondestructively evaluated by electrically characterizing its complex dielectric constant. The real part of the dielectric constant depicts the velocity of electromagnetic waves in PCC. The imaginary part, termed the “loss factor,” describes the conductivity of PCC and the attenuation of electromagnetic waves.Dielectric properties of PCC have been investigated in a laboratory setting using a parallel plate capacitor operating in the frequency range of 0.1 to 40.1MIHz. This capacitor set-up consists of two horizontal-parallel plates with an adjustable separation for insertion of a dielectric specimen (PCC). While useful in research, this approach is not practical for field implementation. A new capacitor probe has been developed which consists of two plates, located within the same horizontal plane, for placement upon the specimen to be tested. Preliminary results show that this technique is feasible and results are promising; further testing and evaluation is currently underway.

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