scholarly journals Correlations between the Properties of Crushed Fine Aggregates

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 86 ◽  
Author(s):  
Revecca Fournari ◽  
Ioannis Ioannou

Aggregates are essential in the production of composite building materials and their properties and characteristics influence the performance of these materials in use. Nevertheless, despite the existence of several standardized and other methods for testing aggregates, the inherent inhomogeneity of these geomaterials does not permit the establishment of rigid specifications for their quality. Hence, research on aggregate testing and quality control is always timely. This paper presents the results of standardized (soundness, Micro-Deval, sand equivalent, methylene blue, water absorption, and relative density) and non-standardized (PXRD) laboratory tests performed on crushed fine aggregates of different mineralogical composition quarried in Cyprus. From these results, it is evident that the mineralogical composition of aggregates affects their physicomechanical properties. A good correlation was observed between the magnesium sulphate soundness coefficient and the Micro-Deval coefficient. This may lead to the introduction of an alternative test method for the quality testing of fine aggregates at European level. A reasonable correlation was also noted between the methylene blue and sand equivalent test results, despite the fact that the literature does not seem to support such a relationship. No further correlations were observed among the rest of the properties investigated.

1982 ◽  
Vol 45 (13) ◽  
pp. 1257-1260 ◽  
Author(s):  
DALE L. SCHEUSNER

Methods to evaluate germicides can be grouped into three categories: standard laboratory tests, in-use tests and simulated-use tests. Standard laboratory methods, such as the Available Chlorine Germicidal Equivalent test, are specifically defined for reproducibility in any laboratory by any operator, but the test results often lack relevance to actual product-use conditions. In-use test methods are relevant to product-use; however, in-use test procedures do not permit proper controls to be included in the organism recovery methods. Contact plates give an estimate of organism numbers which is only 25% of the theoretical number of organisms present. Organism recovery using a swab, cellulose sponge or tube sampler give estimates of organisms ranging from 91 to 111% of theoretical. The tube sampler is a 1-in. length of flexible tubing having a 1-in. interior diameter and a smooth end, which can make a water-tight seal on a flat surface. Simulated use testing yields data which are relevant to actual product-use. A cafeteria tray is soiled, inoculated and cleaned in a manner to simulate actual product-use. This test method permits the necessary controls to be used. Tray-test reproducibility is as good as that of the other recovery methods tested and organism recovery is quantitative. The tray test provides a means for determining biological cleaning where the effect of both cleaning and germicidal activity are measured together.


Author(s):  
Prithvi S. Kandhal ◽  
Rajib B. Mallick ◽  
Mike Huner

Bulk specific gravity of the fine aggregate is used in hot-mix asphalt volumetric-mix design (including Superpave) to determine the amount of asphalt binder absorbed by the aggregate and the percentage of voids in the mineral aggregate. The current test method (AASHTO T84) uses a cone method to establish the saturated surface dry (SSD) condition of the sample, which is necessary to conduct the test. This method does not work satisfactorily for fine aggregates that are very angular and have rough surface texture and, therefore, do not slump readily when in SSD condition. A research project was undertaken to develop automated equipment and a method of establishing the SSD condition of the fine aggregate. The wet sample of the fine aggregate is placed in a rotating drum and subjected to a steady flow of warm air. The temperature gradient of the incoming and outgoing air and the relative humidity of the outgoing air are monitored to establish the SSD condition. Two prototype devices were constructed. The test results obtained with the second prototype device are encouraging and are reported. Further improvements to be made to the second prototype device to improve the repeatability and reproducibility of the test have been identified.


2010 ◽  
Vol 146-147 ◽  
pp. 1529-1535 ◽  
Author(s):  
Miao Yu ◽  
Guo Xiong Wu

There is a comparison among the six Methylene Blue testing methods from different areas and institutes which respectively belong to China, U.S. and Britain. So as to improve the current MBV test of powdery lot used in asphalt mixture in China,it is found that current MBV test needs to be improved by analyzing powder lot Suspension、the concentration of Methylene Blue solution、stirring speed、powder lot types, temperature and soil content. So the revising suggestion to test method T0349-2005 included in standard JTG E42- 2005 is put forward. Later in the micro-surfacing test it is found that by adjusting the silt content, the water damage resistance and anti-abrasion abilities have been affected significantly which are good related to the MBV test recommended in this paper, so it is evident that the improved MBV test is crucial to the quality control over fine aggregates.


2018 ◽  
Vol 138 (11) ◽  
pp. 914-922
Author(s):  
Masashi Kotari ◽  
Tomo Tadokoro ◽  
Shin-ichi Tanaka ◽  
Mikimasa Iwata

Author(s):  
Marina Vasilenko ◽  
Marina Vasilenko ◽  
Elena Goncharova ◽  
Elena Goncharova ◽  
Yury Rubanov ◽  
...  

The surfaces of building materials of hydrotechnical constructions undergo the process of algae biofouling. The degree of damage depends on the environmental factors that are affect-ed by the level of anthropogenic load areas. Modeling the biofouling process of concrete with algae under laboratory conditions has allowed determining their impact on the building ma-terial, accompanied by changes in chemical and mineralogical composition of the surface of products. The microscopic examination of sample’s surfaces and evaluation of the effective-ness of various ions leaching from building materials shows the results of "algal attack" relat-ed to the acceleration of biodegradation of materials under the influence of aggressive meta-bolic products, mechanical action neoplasms, creating optimal conditions for the development of subsequent aerobic microbial decomposers. To clarify the nature of chemical processes in the system “algocenosis – concrete” the changes of chemical and phase (mineralogical) com-position of the surface layer of concrete sample were studied. The effect that algae produce on hydraulic engineering constructions is due to the fact that these organisms, belonging to phototrophs and standing at the beginning of the food chain, initiate new microbial growth.


Author(s):  
Marina Vasilenko ◽  
Marina Vasilenko ◽  
Elena Goncharova ◽  
Elena Goncharova ◽  
Yury Rubanov ◽  
...  

The surfaces of building materials of hydrotechnical constructions undergo the process of algae biofouling. The degree of damage depends on the environmental factors that are affect-ed by the level of anthropogenic load areas. Modeling the biofouling process of concrete with algae under laboratory conditions has allowed determining their impact on the building ma-terial, accompanied by changes in chemical and mineralogical composition of the surface of products. The microscopic examination of sample’s surfaces and evaluation of the effective-ness of various ions leaching from building materials shows the results of "algal attack" relat-ed to the acceleration of biodegradation of materials under the influence of aggressive meta-bolic products, mechanical action neoplasms, creating optimal conditions for the development of subsequent aerobic microbial decomposers. To clarify the nature of chemical processes in the system “algocenosis – concrete” the changes of chemical and phase (mineralogical) com-position of the surface layer of concrete sample were studied. The effect that algae produce on hydraulic engineering constructions is due to the fact that these organisms, belonging to phototrophs and standing at the beginning of the food chain, initiate new microbial growth.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yasin Erdoğan

Handere clay deposits were discovered at Adana in Turkey. These clay units primarily consist of uncoloured claystone, pebbly sandstone, sandstone, siltstone, and mudstone marl and include gypsum lenses and clay levels of various thicknesses in places. The physicochemical properties of these clays have been investigated by different techniques including Scanning Electron and Elemental Analysis (SEM and EDS), mineralogical analyses, chemical and physical analyses, X-ray diffraction (XRD), thermogravimetric differential thermal analysis (TG-DTA), and Atterberg (Consistency) Limits Test. The mineralogical composition deduced from XRD is wide (smectite + palygorskite + illite ± feldspar ± chlorite ± quartz ± calcite ± serpentine) due to the high smectite contents (≈85%). SEM studies reveal that smectite minerals are composed of irregular platy leaves and show honeycomb pattern in the form of wavy leaves in places. The leaves presenting an array with surface edge contact are usually concentrated in the dissolution voids and fractures of volcanic glass. Organic matter content and loss on ignition analysis of raw materials are good for all the studied samples. In summary, Handere clays can be used as building materials in bricks, roof tiles, and cement and as a binder.


2014 ◽  
Vol 496-500 ◽  
pp. 1176-1179
Author(s):  
Li Tan ◽  
Yu Fang

LTX-77 test system is a large IC test system that is used for various kinds of analog IC, digital IC and analog digital mixed IC. It can be used to test DC parameters, AC parameters and logic functions. In the paper, the IC test platform is LTX-77 test system. IC ADC0804 was tested as the test object. The test method of IC is described in the view of actual test. The test results show that the test system is convenient and accurate, which has important practical value for IC manufacturers and users.


Author(s):  
N.I. Konstantinova ◽  
◽  
N.V. Smirnov ◽  
O.V. Krivoshapkina ◽  
O.I. Molchadskiy ◽  
...  

Fiber cement finishing materials are widely used in the construction of industrial buildings and structures due to the complex of valuable operational properties. In the Russian market there are fiber-cement panels with a variety of design solutions for their coloring and application of protective coatings. Fiber cement board is a strong and moisture-resistant composite material made from a cement-sand mixture, reinforcing cellulose fibers and special additives. Not being a non-combustible material, the fiber cement boards in accordance with the current mandatory requirements, as a decorative, finishing and facing material for walls and ceilings have restrictions on their use. Existing domestic requirements regarding the methodology for assessing the combustibility of fiber cement products largely narrow the field of using these materials. Therefore, it is advisable to develop the proposals for amending the test methods and the regulatory framework governing their fire-safe extended scope. In the course of this work execution, the main provisions of the regulatory and methodological framework that establish the requirements for the fire-safe use of fiber cement materials are analyzed. Experimental complex studies of fire hazard properties of various types of samples of the fiber cement finishing panels and slabs were carried out. It is established that fiber-cement materials belong to the class of the least fire-hazardous materials. Advisability is determined concerning the introduction to the national regulatory practice of GOST R «Building materials. Test method for fire hazard under thermal exposure with a single burner (SBI)». Classification parameters of the group of non-combustible materials NG2 were established to amend GOST R 57270—2016 (method 1). Classification parameters of the group of non-combustible materials NG2 for making changes in GOST R 57270—2016 (method 1) are established. Proposals were developed to expand the scope of application of the materials and products made of fiber cement as enclosing structures, partitions, and decorative finishes (cladding) in the buildings and structures.


2018 ◽  
Vol 41 ◽  
pp. 01042
Author(s):  
Vasilii Murko ◽  
Veniamin Khyamyalyainen ◽  
Marina Baranova

Effective utilization of ash-and-slag waste generated by coalfired power plants can help significantly to reduce the negative impact on the environment and improve their economic performance. Studies have been made of the mineralogical composition of ash-and-slag wastes obtained after the combustion of water-coal fuel based on fine-dispersed coal-washing waste (filter cake) in a specially designed boiler with a vortex combustion system. The possibility of effective use of ash-and-slag wastes for the production of building materials, primarily mortar mixes, widely used for mining works on mine openings, laying the worked out space, etc. (high content of silicon oxide and aluminum oxide is combined with a low carbon content in other words a negligible unburned carbon loss). The optimum percentage ratio of the initial components of the filling mixture based on ash-and-slag wastes and crushed rock (granulated slag) has been established. The results of experimental tests of hardening tabs on the strength under uniaxial compression are presented. It has been established that a sample containing 18% of ash-and-slag wastes, 33% of a granulated slag and 19% of cement, corresponds to the required technological parameters for the strength and cement content.


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