Zargoleh, M.R.A., Mazloom, M., Samimi, M.J., Ramesht, M.H.
Amirkabir Journal of Civil Engineering (2588297X)55(3)pp. 723-738
Geopolymer concrete is an innovative building material that is produced by the chemical action of mineral molecules. Removal of cement is one of the great advantages of the use of geopolymer concrete. For this reason, to know the types of geopolymer concrete, it is important to examine its different components and their effect on fracture parameters. In this paper, the fracture parameters of lightweight geopolymer concrete based on class C fly ash (LWFCGC) are presented. In this research, three mix designs with the activator to binder ratios of 0.4, 0.5 and 0.6 were considered. By changing the ratio of activator to glue from 0.6 to 0.4, compressive strength from 18.9 MPa to 28.4 MPa, toughness from 14.07 MPa mm to 19.04 MPa mm 0.5, fracture energy from N/ 17.31 m to 20.98 N/m and the length of the fracture process area changed from 54.12 mm to 29.07 mm.
Tangtakabi a., , Ramesht, M.H., Pahlaviani a.g., A.G., Pourrostam t.,
Amirkabir Journal of Civil Engineering (2588297X)54(8)pp. 2953-2968
Marine structures are considered as infrastructural structures due to their special geographical location and their important share in the country's economy. The most important damage to marine concrete structures in the tidal zone is due to the corrosion of reinforcements in concrete. These conditions reduce the useful life of concrete structures. One of the effective methods to prevent corrosion of reinforcement and reduce the penetration of chloride ions in concrete structures in marine environments is to improve the quality and mechanical properties of concrete using microsilica, although various studies have been conducted on this subject. However, this paper intends to investigate the optimal use of microsilica in reducing reinforcement corrosion in marine concrete structures on the properties of hardened concrete in 18 months and at different times. In the Sample laboratory, with a ratio of water to cement, 34% ,40% and superplasticizer range from 3% to 6%, and the microsilica with the percentages 7,10,13, made, and after the exposed conditions on aggressive, etc. testing corrosion rate, has been measured. The results show that. The effect of concrete mix containing 10% silica fume with a ratio of water to cement 34%, the durability of the reinforcement against corrosion and service life of marine structures increases.
Akhondi, M., Ramesht, M.H., Pourrostam t., , Pahlaviani a.g., A.G.
Amirkabir Journal of Civil Engineering (2588297X)53(3)pp. 1107-1116
In this paper, we examine the simultaneous effect ofpolyethylene terephthalate and silica fume on the rheological and mechanical properties of concrete pavements and looking to present a new mix of green concrete (environmentally friendly concrete) with the use of PET waste materials and silica fume. Due to problems with asphalt pavement, such as endangering the environment, bitumen is expensive and considering that Iran is currently the third-largest producer of cement worldwide. Therefore, concrete pavements have been given special attention today. It also increases the consumption of pet food bottles and, consequently, increaseswaste production, and increasing the waste disposal site adds to the importance of reuse of these wastes. One of the uses of these lesions, without having a destructive effect on the environment, reusing them is to enclose them in concrete rigid pavements. On the other hand, research shows that another piece of waste products in the glass industry which is known as micro silica or silica fume which can be used in concrete pavement. The results from this study indicate the use of pet particles in concrete pavement did not have much impact on compressive strength But in contrast, it increases the tensile strength, bending. In contrast to the use of micro silica, it has increased compressive strength, reduced water absorption, and reduced permeability in concrete pavements.
Rashidi, M., Ramesht, M.H., Zohary, M., Poursafa, P., Kelishadi, R., Rashidi, Z., Rouzbehani, R.
Journal Of Research In Medical Sciences (17357136)18(12)pp. 1074-1079
Background: National Institute of Environmental Health Sciences (NIEHS) scientists shows that long-term exposure to air pollutants increases the risk of respiratory diseases such as allergies, asthma, chronic obstructive pulmonary disease, and lung cancer. Children and the elderly are particularly vulnerable to the health effects of ozone, fine particles, and other airborne toxicants. Air pollution factors are considered as one of the underlying causes of respiratory diseases. This study aimed to determine the association of respiratory diseases documented in medical records and air pollution (Map distribution) of accumulation in Isfahan province, Iran. By plotting the prevalence and spatial distribution maps, important differences from different points can be observed. Materials and Methods: The geographic information system (GIS), pollutant standards index (PSI) measurements, and remote Sensing (RS) technology were used after entering data in the mapping information table; spatial distribution was mapped and distribution of Geographical Epidemiology of Respiratory Diseases in Isfahan province (Iran) was determined in this case study from 2005 to 2009. Results: Space with tracing the distribution of respiratory diseases was scattered based on the distribution of air pollution in the points is an important part of this type of diseases in Isfahan province where air pollution was more abundant. Conclusion: The findings of this study emphasis on the importance of preventing the exposure to air pollution, and to control air pollution product industries, to improve work environmental health, and to increase the health professionals and public knowledge in this regard.
Journal of Isfahan Medical School (10277595)29(125)
Background: Cardiovascular disease is one of the most prevalent diseases in the world and it is expected to be the main cause of death by 2020. The aim of this study was providing geographical distribution map of the rate of death caused by cardiovascular diseases in the cities of Isfahan province, Iran, during 2005 to 2009. Methods: The rate of all the deaths in Isfahan province within 2005 to 2009 was provided. The collected data was used to find out the rate of deaths due to cardiovascular diseases and preparing geographical distribution maps. Then, by putting down the death rates for different sexes (men and women), the geographical distribution map for deaths with regards to cardiovascular diseases was drawn. Finding: Death rates due to cardiovascular problems were higher in main and central cities of the province. Death rate was higher in men than women. Conclusion: The observed model main and central cities is probably due to unsuitable diet, lack of motion, using new technologies and environmental pollutions including existence of some elements due to environmental pollutants such as industries, transportations of vehicles and air pollution, which are more prevalent in the main cities of the province. Also, due to existence of medical university centers and more health facilities in the main cities of the province, such as Isfahan, Najafabad, Borkhar and Maymeh, the registration system for deaths and diagnosing the causes of deaths are more accurate than other cities and towns of the province. The difference between two sexes could be due to in heritage, male hormones, some social factors, increasing fat around abdomen in men, exciting or even offensive behaviors in men, ignoring weight increase in men as compared to women and smoking.
Ferrocement is a type of thin wall reinforced concrete construction where real composite action between the matrix phases and the reinforcement exists. This composite action results in excellent control of cracking, high tensile strength and durability [1]. This investigation is concerning with the experimental and theoretical behavior of ferrocement under tension. The effects of different arrangements of mesh reinforcement, with particular respect to the specimen thickness and mortar cover, on the cracking behavior and both first crack strength and ultimate strength were studied. The mechanical properties of the wire mesh and mortar which was used in this investigation were also studied. The results show that, under direct tension, the strength of ferrocement at first crack and ultimate load is not affected significantly by the arrangement of the reinforcement. However, specimens having reinforcement evenly distributed with minimum cover showed reduced crack widths and an increased number of small cracks at failure. The contribution of the tensile strength of the mortar and the specimen thickness on first crack strength is considered to be significant, while it can be considered negligible at ultimate strength.
The aim of this paper is to review and compare various analytical procedures which have been developed to predict the ultimate moment of ferrocement under flexure. One such procedure has been used as the basis of the computer program FAOFERRS, which has then been used to compare predictions with experimental results for specimens having various mesh arrangements. An attempt is made to predict the ultimate moment for specimens reported by other investigators and the results are compared and discussed.
Over the past decade, corrosion became a crucial problem on two counts: (a) it is expensive to repair and (b) it has widespread occurrence. The research evaluated the effects of corrosion on the properties and flexural behavior of ferrocement. Two series of specimens were tested. The first series were cast, placed in water and a suitable environment for 28 days, and then subjected to flexural test. The second series were placed in a weather simulator tank, with corrosive environmental conditions and after three months, were tested for flexure. From a careful examination of the results of the flexural tests it emerges that: 1. The presence of NaCl and temperature, as well as the prevalence of wet and dry conditions, have a considerable effect on the flexural behavior of ferrocement: it increases the brittleness of mortar, reduces the number of cracks and increases the crack width. 2. Slight increase in the first crack strength and maximum strength of specimens. 3. The effect of corrosion in reducing the strength of ferrocement specimens with ungalvanized wire meshes, is greater than its effect on specimens with galvanized wire meshes.
Ferrocement has been increasingly used as a structural material which competes favorably with reinforced concrete and other building materials. The durability of ferrocement depends on several factors including the quality of ferrocement, mesh type, depth of cover over the mesh, the direction and magnitude of applied load(s) and its resistance to corrosion. Corrosion of mesh reinforcement in ferrocement is one of the important aspects which has not received sufficient attention from research workers. This paper presents the results of monitoring the corrosion performance of ferrocement specimens exposed to extremely aggressive conditions (6% NaCl solution at 60°C). Several parameters have been considered in this study, including type and arrangement of mesh reinforcement and depth of mortar cover over the meshes. Four methods were used for corrosion examination of the specimens; visual examination, corrosion potential, corrosion rate and microscopic examination.
