scholarly journals Modeling the composition of fine-grained modified concrete elaborated with vibropressing technology

2019 ◽  
Vol 298 ◽  
pp. 00133 ◽  
Author(s):  
E. R. Pyataev ◽  
A. Y. Ushakov
Keyword(s):  
Portland Cement ◽  
Experimental Research ◽  
Frost Resistance ◽  
Building Materials ◽  
Road Construction ◽  
Average Density ◽  
Optimal Composition ◽  
Fine Grained ◽  
Main Components ◽  
Modifying Additive

The article analyzes the property requirements of small-piece products used in road construction, specially those related to water and frost resistance. It describes the main features of the vibration technologies involved in the manufacture of building materials, in particular, paving slabs. The article presents conclusive results, obtained through scientific research, which allow us to establish the influence of both, the costs of the main components and the parameters of vibration compression, on the properties of the final product. Combining the analysis of classical methods with the results of experimental research, a methodology has been developed for reaching an optimal composition of fine-grained vibropressed concrete modified with active additives. It is shown that the particular strength achieved from the combination of vibroformed fine-grained concrete, whose average density is 2270–2320 kg/m3, with polymer multifunctional modifiers, is mainly due to the use of Portland cement, a modifying additive, and the pressure conditions employed during the experiment..

scholarly journals The effect of ashes on the properties of cement mortar and typical concrete fillers

2019 ◽  
Author(s):  
Janina Setina ◽  
Inna Juhnevica ◽  
Janis Baronins
Keyword(s):  
Portland Cement ◽  
Mechanical Strength ◽  
Frost Resistance ◽  
Building Materials ◽  
Cement Mortar ◽  
Hardened Concrete ◽  
Short Term ◽  
Lightweight Structures ◽  
Active Additive

The production of heat and electricity from shale and biomass is leading to a significant increase in the amount of the combustion residues i.e. ashes. The utilization of ashes as the pozzolanic additive in the production of Portland cement mortar and concrete for the construction of lightweight structures is the most popular way. The interaction of ashes with other typical concrete fillers also can affect the final relative short-term and long-term properties of fresh and hardened concrete when designing the concrete mixture. The influence of wood and shale ashes on the properties of cement mortar and typical concrete fillers (sand, limestone, dolomite) – fresh mortar, hydration process, and hardened mortar were researched and assessed for their applicability in the production of concrete. The best results of mechanical strength, frost resistance and water absorption were measured in case of shale ashes containing samples in combination with cement and selected concrete additive – sand. Shale ashes can be recommended for application as the active additive. Since wood ash was exhibiting lower activity, it can also be applied as a filler to produce building materials.

scholarly journals Frost resistance of cement composites prepared on the basis of waste water from a concrete plant

2018 ◽  
Vol 13 (1) ◽  
pp. 123-132
Author(s):  
Lukas Klus ◽  
Vojtech Vaclavik ◽  
Jakub Svoboda ◽  
Jindrich Sancer
Keyword(s):  
Waste Water ◽  
Portland Cement ◽  
Experimental Research ◽  
Frost Resistance ◽  
Resistance Coefficient ◽  
Resistance Test ◽  
Cement Composites ◽  
Recycled Water ◽  
Recycled Waste ◽  
Mixing Water

Abstract This article presents the results of a research dealing with the use of waste water from concrete industry as a possible substitution of mixing water during the production of cement composites. This experimental research involved the preparation of two recipes of cement composites, named R1 and R3. Mixing water in these recipes was replaced with waste water from a concrete plant in the amount of 25, 50, 75 and 100%. Samples of recycled waste water, which were tested for the content of sulphates, chlorides and alkali according to ČSN EN 1008, were taken in order to determine the properties of waste water from a concrete plant. The prepared test specimens were tested for frost resistance after 100 freezing cycles according to ČSN 73 1322. The results of the frost resistance test showed that the required value of the frost resistance coefficient of 0.75 according to ČSN 73 1322 was achieved only in case of recipe R1 based on Portland cement CEM I 52.5R and 75 and 100% substitution of the mixing water with recycled water from a concrete plant.

scholarly journals Cement Render and Mortar and Their Damages Due to Salt Crystallization in the Holy Trinity Church, Dominicans Monastery in Cracow, Poland

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 641 ◽  
Author(s):  
Mariola Marszałek ◽  
Krzysztof Dudek ◽  
Adam Gaweł
Keyword(s):  
Portland Cement ◽  
Building Materials ◽  
Cement Mortar ◽  
Cement Clinker ◽  
Anthropogenic Factors ◽  
Salt Crystallization ◽  
13Th Century ◽  
Holy Trinity ◽  
Fine Grained ◽  
Rock Fragments

The investigations focused on the façade of the 17th-century Myszkowskis chapel at the 13th-century Church of the Holy Trinity in Cracow, Poland. Most of the chapel’s façade is made of rusticated limestone blocks, but its lower part is covered with cement render, and the basement consists of irregular pieces of limestone and sandstone, bound and partly replaced with cement mortar. The façade exhibited clearly visible damages: gray soiling of the surface, cracks, scaling, and efflorescence. The study presents characteristics of the cement render and mortar used for stone repair and/or substitution, as well as efflorescence from the lower part of the Myszkowskis chapel façade. The materials were analyzed with optical microscopy, scanning electron microscopy (SEM-EDS), Raman microspectroscopy, X-ray diffractometry (XRPD), and mercury intrusion porosimetry. The analyses demonstrated that the render covering some of the decayed limestone blocks was prepared using Portland cement (residual clinker grains represent alite and belite) as a binding agent, mixed with crushed stone as an aggregate. The cement mortar consisted of rounded quartz grains, rock fragments, and feldspars in very fine-grained masses of calcite and gypsum, also containing relics of cement clinker (alite, belite, ferrite, and aluminate). All these components point out the use of the ordinary Portland cement. Analyses of the efflorescence allowed us to distinguish several secondary salts, among others, thenardite, aphthitalite, and darapskite. The appearance of these phases is related to the composition and physicochemical properties of the building materials, atmospheric alteration agents, air pollution, and some other anthropogenic factors.

Properties of Magnesium Oxychloride and Magnesium Oxysulphate Cement Composites

2021 ◽  
Vol 903 ◽  
pp. 208-213
Author(s):  
Elvija Namsone ◽  
Genadijs Sahmenko ◽  
Aleksandrs Korjakins
Keyword(s):  
Mechanical Properties ◽  
Energy Consumption ◽  
Portland Cement ◽  
Calcination Temperature ◽  
Experimental Research ◽  
Magnesium Sulphate ◽  
Magnesium Chloride ◽  
Building Materials ◽  
Cement Composites ◽  
Magnesium Oxychloride

Increasing energy consumption is forcing the building sector to seek and use building materials and products that would be environmentally friendly. As one such material should be noted magnesium based cements, which production requires much lower calcination temperature than the traditional Portland cement. During the experimental research part of this work, two types of magnesia cement were produced (using magnesium chloride and magnesium sulphate brine solutions) and physical, mechanical properties of obtained cement composites were determined.

The Use of Metallurgical Wastes in Road Construction

2018 ◽  
Vol 931 ◽  
pp. 674-678
Author(s):  
Rashid R. Sharapov ◽  
Evgeny V. Kharlamov ◽  
Talgat R. Gabdullin
Keyword(s):  
Fluidized Bed ◽  
Quartz Sand ◽  
Building Materials ◽  
Road Construction ◽  
Fine Grained ◽  
Mill Tailings ◽  
Metallurgical Wastes ◽  
Iron Bearing

The proposed method is a dry separation tailings. A separator developed for separating the tailings of the quartz sand and iron-bearing components. The efficiency of separation of enrichment tails in the fluidized bed separator is shown. The use of mill tailings as components in the manufacture of building materials is practically confirmed by testing samples of fine-grained concrete and asphalt.

Experimental Research of Building Materials Based on the Natural Cellulosic Fibers under Biogenic Acidic Exposition

2015 ◽  
Vol 1 (5) ◽  
pp. 250-254
Author(s):  
Adriana Eštoková ◽  
Alena Luptáková ◽  
Martina Kovalčíková ◽  
Nadezda Stevulova
Keyword(s):  
Experimental Research ◽  
Building Materials ◽  
Cellulosic Fibers

Experimental Research on the Qualitative Characteristics of Iron Ores and Ferrous Waste That Can Be Used in Blast Furnace Mixt Injection Technology

2019 ◽  
Vol 70 (11) ◽  
pp. 3835-3842
Author(s):  
Mihai Dumitru Tudor ◽  
Mircea Hritac ◽  
Nicolae Constantin ◽  
Mihai Butu ◽  
Valeriu Rucai ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Experimental Research ◽  
Raw Materials ◽  
Coal Dust ◽  
Production Costs ◽  
Iron Ores ◽  
Fine Grained ◽  
Experimental Laboratory ◽  
Injection Technology ◽  
Direct Use

Direct use of iron ores in blast furnaces, without prior sintering leads to a reduction in production costs and energy consumption [1,2]. Fine-grained iron ores and iron oxides from ferrous wastes can be used together with coal dust and limestone in mixed injection technology through the furnace tuyeres. In this paper are presented the results of experimental laboratory investigations for establishing the physic-chemical characteristics of fine materials (iron ore, limestone, pulverized coal) susceptible to be used for mixed injection in blast furnace. [1,4]. The results of the experimental research have shown that all the raw materials analyzed can be used for mixt injection in blast furnace.

scholarly journals Special Issue: Supplementary Cementitious Materials in Concrete, Part I

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2291
Author(s):  
Alessandro P. Fantilli ◽  
Daria Jóźwiak-Niedźwiedzka
Keyword(s):  
Environmental Impact ◽  
Portland Cement ◽  
Building Materials ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Special Issue ◽  
Cement Production ◽  
Concrete Part

The environmental impact of the Portland cement production and the large use of cement-based building materials is a growing problem [...]

Modelling of Flow Properties of Asphalt Mastics

2013 ◽  
Vol 752 ◽  
pp. 209-216 ◽  
Author(s):  
Róbert Géber ◽  
László A. Gömze
Keyword(s):  
Research Work ◽  
Road Construction ◽  
Test Results ◽  
Flow Properties ◽  
Rheological Models ◽  
Fine Grained ◽  
Mineral Particles ◽  
Asphalt Mastics ◽  
Rheological Modelling ◽  
Mineral Fillers

The present research work deals with the examination and rheological modelling of flow properties of asphalt mastics which are the most important components of asphalt concretes. Asphalt mastics are mixtures of fine grained mineral filler particles (d<0,063 mm) and bitumen, having a stabilizing role in asphalt mixtures and largely determining the cohesion between mineral particles and bitumen. During our examinations two types of mineral fillers – limestone and dolomite – as well as standard bitumen were tested, which are extensively used in Hungarian road construction. Asphalt mastic mixtures were prepared out of these materials and they were tested with dynamic shear rheometer (DSR). According to the test results, rheological models of mastics were determined. It has been established that at different test temperatures and shear rate ranges asphalt mastics behave as Herschel-Bulkley and Bingham-type materials.

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