Durability Properties of High Performance Concrete Containing High Volumes of Supplementary Cementitious Materials

An experimental study was conducted to evaluate the performance of high performance non-air entrained concrete containing various supplementary cementitious materials. Concrete was prepared for constant value of slump and water-binder ratio. Fresh properties were determined in terms of slump and air content, whereas, hardened properties were investigated in terms of mechanical and durability tests. The maximum carbonation depth observed for concrete exposed for a period of sixteen weeks containing 40% pulverized fuel ash and 7.5% microsilica was about 5 mm. The non-steady state migration and diffusion coefficient of concrete containing different type of supplementary cementitious materials were observed to be appreciably lesser than that of the control concrete. The coefficient was noted to be least one for concrete with 15% microsilica. When 7.5% microsilica was used in 40% pulverized fuel ash and 50% ground granulated blast-furnace slag concrete, the improved resistivity (in terms of lower value) was observed than that exhibited by 15% microsilica concrete. However, both the ternary mixes showed better resistivity values when compared with control concrete. The scaled mass in kg/m2 for 40% pulverized fuel ash concrete was the maximum among all the mixes. Addition of 7.5% microsilica in concrete did not cause any considerable change in the scaled mass. However, the increased content (15%) of microsilica behaved excellently in reducing the scaled mass. Ternary mixes of 40% pulverized fuel ash and 50% ground granulated blast-furnace slag concrete were found to show reduction in scaled mass

Performance of Self Compacting Concrete Using Bentonite

Supplementary Cementitious Materials (SCMs) have the potential to enhance the properties of self-compacting concrete (SCC) while reducing the pressure on natural reserves and CO2 emissions. However, certain SCMs are not able to meet the needs in the construction industry. This research investigates the role of unheated bentonite (BN) clay and its synergistic effect with Ground Granulated Blast Furnace Slag (GGBS) as a partial substitute for cement on performance of SCC. Three different mixtures were prepared, each consisting of 0%, 15%, and 30% (by weight) BC as a replacement for cement, while GGBS remained constant to get the designed strength. Each mix was designed with two strength grades of 30 and 60 MPa by adjusting the compositional parameters and validating their 28 days compressive strength. Fresh Properties tests were conducted as per EFNARC standards. The ultrasonic pulse velocity of all tested specimens is greater than 4.5 km/s, indicating "good" and "excellent" quality concrete. The experimental results revealed that combining BC with GGBS concrete improved durability. The BC and GGBS made concrete more resistant to sulphate attack and chloride ingress. The concrete mixtures were found to be suitable and more durable for use in the construction industry

Cancer diagnosis using deep learning: A bibliographic review

In this paper, we first describe the basics of the field of cancer diagnosis, which includes steps of cancer diagnosis followed by the typical classification methods used by doctors, providing a historical idea of cancer classification techniques to the readers. These methods include Asymmetry, Border, Color and Diameter (ABCD) method, seven-point detection method, Menzies method, and pattern analysis. They are used regularly by doctors for cancer diagnosis, although they are not considered very efficient for obtaining better performance. Moreover, considering all types of audience, the basic evaluation criteria are also discussed. The criteria include the receiver operating characteristic curve (ROC curve), Area under the ROC curve (AUC), F1 score, accuracy, specificity, sensitivity, precision, dice-coefficient, average accuracy, and Jaccard index. Previously used methods are considered inefficient, asking for better and smarter methods for cancer diagnosis. Artificial intelligence and cancer diagnosis are gaining attention as a way to define better diagnostic tools. In particular, deep neural networks can be successfully used for intelligent image analysis. The basic framework of how this machine learning works on medical imaging is provided in this study, i.e., pre-processing, image segmentation and post-processing. The second part of this manuscript describes the different deep learning techniques, such as convolutional neural networks (CNNs), generative adversarial models (GANs), deep autoencoders (DANs), restricted Boltzmann’s machine (RBM), stacked autoencoders (SAE), convolutional autoencoders (CAE), recurrent neural networks (RNNs), long short-term memory (LTSM), multi-scale convolutional neural network (M-CNN), multi-instance learning convolutional neural network (MIL-CNN). For each technique, we provide Python codes, to allow interested readers to experiment with the cited algorithms on their own diagnostic problems. The third part of this manuscript compiles the successfully applied deep learning models for different types of cancers. Considering the length of the manuscript, we restrict ourselves to the discussion of breast cancer, lung cancer, brain cancer, and skin cancer. The purpose of this bibliographic review is to provide researchers opting to work in implementing deep learning and artificial neural networks for cancer diagnosis a knowledge from scratch of the state-of-the-art achievements

Performance of Self Compacting Concrete Using Bentonite

Supplementary Cementitious Materials (SCMs) have the potential to enhance the properties of self-compacting concrete (SCC) while reducing the pressure on natural reserves and CO2 emissions. However, certain SCMs are not able to meet the needs in the construction industry. This research investigates the role of unheated bentonite (BN) clay and its synergistic effect with Ground Granulated Blast Furnace Slag (GGBS) as a partial substitute for cement on performance of SCC. Three different mixtures were prepared, each consisting of 0%, 15%, and 30% (by weight) BC as a replacement for cement, while GGBS remained constant to get the designed strength. Each mix was designed with two strength grades of 30 and 60 MPa by adjusting the compositional parameters and validating their 28 days compressive strength. Fresh Properties tests were conducted as per EFNARC standards. The ultrasonic pulse velocity of all tested specimens is greater than 4.5 km/s, indicating "good" and "excellent" quality concrete. The experimental results revealed that combining BC with GGBS concrete improved durability. The BC and GGBS made concrete more resistant to sulphate attack and chloride ingress. The concrete mixtures were found to be suitable and more durable for use in the construction industry

Performance of Fibre Reinforced Self Compacting Concrete against Chloride Attack

This paper presents the combined effect of polypropylene fibres (PPF), silica fume (SF), and fly ash (FA) on the characteristics of normal strength self-compacting concrete (NSSCC). NSSCC is proposed to be prepared by several combinations of PPF and class C FA as partial replacement of cement. NSSCC was prepared by incorporation of SF at 10% and PPF at 0.5%, 1%, and 1.5% by mass of Portland cement. Cohesion and adhesion properties of concrete become much better, along with increased tightness and excellent deformability due to the binding strength of PPF. These fibres inhibit the formation of pores in the concrete matrix and prevent the crack formation and its spread along with the matrix. The chloride migration coefficient was determined in accordance with NT Build 492. Mass diffusivity of chloride ions reduces with increasing concentrations of fly ash in concrete. Results indicate that fibre-reinforced concrete has the improved durability compared to other methods

Effects of Incorporating Fiber Cocktail on Mechanical Properties of Concrete

The objective of this research work was to determine the effect of fiber cocktail on mechanical properties of concrete. Three types of fibers were used namely monofilament polypropylene fiber, steel fiber and glass fiber. Steel and glass fiber were incorporated in concrete at different dosages while the content of Polypropylene fiber was kept constant. For this purpose, cubes (150×150×150mm) and prisms (101×101×508mm) were casted for compressive strength test on cubes and Two-Point load test on prisms. Eighteen different mixes were prepared such as control mix, single fiber concrete, double hybrid concrete and triple hybrid concrete. It was observed that both compressive and flexural strength increased with addition of single, double and triple fibers. However, the strengths of triple hybrid concrete were observed to be lesser as compared to single and double hybrid concrete

Effects of Incorporating Fiber Cocktail on Mechanical Properties of Concrete

The objective of this research work was to determine the effect of fiber cocktail on mechanical properties of concrete. Three types of fibers were used namely monofilament polypropylene fiber, steel fiber and glass fiber. Steel and glass fiber were incorporated in concrete at different dosages while the content of Polypropylene fiber was kept constant. For this purpose, cubes (150×150×150mm) and prisms (101×101×508mm) were casted for compressive strength test on cubes and Two-Point load test on prisms. Eighteen different mixes were prepared such as control mix, single fiber concrete, double hybrid concrete and triple hybrid concrete. It was observed that both compressive and flexural strength increased with addition of single, double and triple fibers. However, the strengths of triple hybrid concrete were observed to be lesser as compared to single and double hybrid concrete

CAUSES OF DELAY AND COST OVERRUNS DURING CONSTRUCTION PROJECTS IN DEVELOPING COUNTRIES; A CASE STUDY OF PAKISTAN

Construction projects are frequently delayed due to price escalation of building materials in Pakistan. This research work focused on the main causes of delay is exclusively assessed through questionnaire survey, field visits and discussions to the concerned authorities. A survey was conducted through a questionnaire for identification and evaluation of the important factors result in increasing the cost of materials and delay of construction work in Pakistan. This survey had respondents from client, contractor and consultant firms involved in construction industry. At the same time general public was also a part of it so that an idea about country’s trend would have to be evaluated. The results attained from survey revealed that the major causes of obstacles are the increase in cost of construction materials and delayed due to non-availability of funds in developing countries.According to the contractors escalation of prices is the significant factor for delays in work and cost escalation. The consultants are blaming the poor supervision by contractors. The overall ranking are indicating that all the groups feel that the major factors causing construction delays and overruns in Pakistan are increase of prices, poor contract supervision, monthly payment, hindrances from agencies and shortage of material in their degree of influence

Assessment Of Variation In Soil Parameters, For Design Of Lightly Loaded Structural Foundations

ABSTRACT: Assessment of variation in soil parameter is required to proceed for structural design of foundations. This study aims to develop the zoning of the project area on the bases of extensive experimental work in laboratory and field tests performed at the number of locations of the project area. The zones are developed based on similar characteristics of different soil parameters. The data points have been marked on the base map of the study area along with the boundaries of the zones. The experimental data of the study area has shown potential for development of three zones. The subsurface soils in zone A consist of low plastic fill material up to 2.0 m depth overlaying low plastic clay from 2.0 m to 4.0 m and low plastic clay/clayey silt beyond 4.0 m depth. Zone B consists of low plastic clay and clayey silt up to the depth of 4. meter overlaying clayey silt to silt with sand material from 4.0 m to 6 m depths and gravel with sand beyond 6.0 meter depth. In zone C, low plastic clay/clayey silt is found up to 2.0 m depth overlaying silty sand up to 4.0 m depth and gravel with sand beyond 4.0 m depth. Number of blows (N Value) of standard penetration test (SPT) for Zone A is less than 8, for Zone B, it ranges from 8-15 and for Zone C, N value is greater than 15. The resultant data can be helpful during planning stage of the project and during feasibility study of mega projects. The research work is extendable to develop the geotechnical zoning map of any specific area and it can be part of building code