The Influence of the Environment on the Properties of Hybrid Cement-Based Concrete with Steel and Air-Cooled Slags

This article presents the results of research that dealt with the development of non-traditional concrete using a hybrid alkali-activated cement. It is concrete based on by-products from a metallurgical plant that replaced 100% of the natural aggregates. Steel slag (CSS, fraction: 0/8 mm) was used as a filler in combination with air-cooled slag (ACBFS, fraction: 8/16 mm and 16/32 mm). Portland blended cement (CEM II/B-S 42.5N) and H-CEMENT were used as binding components in the development of the concrete mixture designs. Both of these cements were produced by Považská cementáreň, a.s., Ladce. Attention was focused on testing the physical and mechanical properties of the developed concretes in various environments. An aqueous environment was selected as the first environment for the placement of test specimens (cubes with 150 mm edges and prisms with dimensions of 100 × 100 × 400 mm3) according to the ČSN EN 206-1 standard and the outdoor environment (August to October). The determination of the cube strength was made after 7, 28, and 90 days, the determination of the flexural and compressive strength was made at the end of the prisms, and the determination of the dynamic modulus of elasticity was made after 28 days on the prisms. The test results of the test specimens, which were placed in two environments, were compared and it was found that, after 90 days, the outdoor environment caused a decrease in the concrete’s strength characteristics when using Portland blended cement (CEM II/ B-S 42.5N) of about 8%; in contrast, when using H-CEMENT, the concrete’s strength increased by about 14%. The use of H-CEMENT and the addition of PUZZOLANIT in the amount of 30% in combination with CEM II/B-S 42.5N in the amount of 70% reduced the decrease in the strength of the concrete after 90 days by about 3%. The research results confirm the suitability of using H-CEMENT and the addition of PUZZOLANIT for the production of concrete based on steel slag (CSS) and air-cooled slag (ACBFS).

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Mortars with Recycled Aggregates from Building-Related Processes: A ‘Four-Step’ Methodological Proposal for a Review

Sustainability ◽

10.3390/su13052756 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2756

Author(s):

Federica Vitale ◽

Maurizio Nicolella

Keyword(s):

Building Materials ◽

Thermal Analyses ◽

Construction Materials ◽

Physical And Mechanical Properties ◽

Research Trends ◽

Mix Design ◽

Recycled Aggregates ◽

Design Parameters ◽

Natural Aggregates ◽

By Products

Because the production of aggregates for mortar and concrete is no longer sustainable, many attempts have been made to replace natural aggregates (NA) with recycled aggregates (RA) sourced from factories, recycling centers, and human activities such as construction and demolition works (C&D). This article reviews papers concerning mortars with fine RA from C&D debris, and from the by-products of the manufacturing and recycling processes of building materials. A four-step methodology based on searching, screening, clustering, and summarizing was proposed. The clustering variables were the type of aggregate, mix design parameters, tested properties, patents, and availability on the market. The number and the type of the clustering variables of each paper were analysed and compared. The results showed that the mortars were mainly characterized through their physical and mechanical properties, whereas few durability and thermal analyses were carried out. Moreover, few fine RA were sourced from the production waste of construction materials. Finally, there were no patents or products available on the market. The outcomes presented in this paper underlined the research trends that are useful to improve the knowledge on the suitability of fine RA from building-related processes in mortars.

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Compressive Strength, Chloride Ion Penetrability, and Carbonation Characteristic of Concrete with Mixed Slag Aggregate

Materials ◽

10.3390/ma13040940 ◽

2020 ◽

Vol 13 (4) ◽

pp. 940

Author(s):

Se-Jin Choi ◽

Young-Uk Kim ◽

Tae-Gue Oh ◽

Bong-Suk Cho

Keyword(s):

Compressive Strength ◽

Steel Slag ◽

Chloride Ion ◽

Fine Aggregate ◽

Test Results ◽

Replacement Ratio ◽

Concrete Aggregates ◽

The Social ◽

Ferronickel Slag ◽

Natural Aggregates

The shortage of natural aggregates has recently emerged as a serious problem owing to the tremendous growth of the concrete industry. Consequently, the social interest in identifying aggregate materials as alternatives to natural aggregates has increased. In South Korea’s growing steel industry, a large amount of steel slag is generated and discarded every year, thereby causing environmental pollution. In previous studies, steel slag, such as blast furnace slag (BFS), has been used as substitutes for concrete aggregates; however, few studies have been conducted on concrete containing both BFS and Ferronickel slag (FNS) as the fine aggregate. In this study, the compressive strength, chloride ion penetrability, and carbonation characteristic of concrete with both FNS and BFS were investigated. The mixed slag fine aggregate (MSFA) was used to replace 0, 25%, 50%, 75%, and 100% of the natural fine aggregate volume. From the test results, the highest compressive strength after 56 days was observed for the B/F100 sample. The 56 days chloride ion penetrability of the B/F75, and B/F100 samples with the MSFA contents of 75% and 100% were low level, approximately 34%, and 54% lower than that of the plain sample, respectively. In addition, the carbonation depth of the samples decreased with the increase in replacement ratio of MSFA.

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La formation des liaisons éthériques lors de la production du polytéréphthalate d'éthylène glycol

Canadian Journal of Chemistry ◽

10.1139/v78-445 ◽

1978 ◽

Vol 56 (21) ◽

pp. 2703-2706 ◽

Cited By ~ 3

Author(s):

Vladimir Hornof ◽

Leoš Zeman

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Ethylene Glycol ◽

Chemical Method ◽

Periodic Acid ◽

Accurate Determination ◽

Physical And Mechanical Properties ◽

Resistance To Oxidation ◽

By Products

Ether-type linkages are formed as by-products during the preparation of polyethylene terephthalate from dimethyl terephthalate and ethylene glycol. Incorporated in the polymer, these linkages affect its physical and mechanical properties such as tensile strength, melting point, and resistance to oxidation. An improved chemical method of analysis has been developed allowing an accurate determination of ether bonds in polyester fibres. The method is based on the selective oxidation of ethylene glycol with periodic acid and takes advantage of hydrolysis with water under pressure to decompose the polymer. The method has been employed to study the effect of the concentration of polycondensation catalyst on the formation of ethers.

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Sustainability Potential Evaluation of Concrete with Steel Slag Aggregates by the LCA Method

Sustainability ◽

10.3390/su12239873 ◽

2020 ◽

Vol 12 (23) ◽

pp. 9873

Author(s):

Vojtěch Václavík ◽

Marcela Ondová ◽

Tomáš Dvorský ◽

Adriana Eštoková ◽

Martina Fabiánová ◽

...

Keyword(s):

Life Cycle ◽

Construction Industry ◽

Raw Materials ◽

Steel Slag ◽

Physical And Mechanical Properties ◽

Partial Replacement ◽

Utilization Rate ◽

Natural Aggregate ◽

Concrete Production ◽

Natural Aggregates

Sustainability in the construction industry refers to all resource-efficient and environmentally responsible processes throughout the life cycle of a structure. Green buildings may incorporate reused, recycled, or recovered materials in their construction. Concrete is as an important building material. Due to the implementation of by-products and waste from various industries into its structure, concrete represents a significant sustainable material. Steel slag has great potential for its reuse in concrete production. Despite its volume changes over time, steel slag can be applied in concrete as a cement replacement (normally) or as a substitute for natural aggregates (rarely). This paper focused on an investigation of concrete with steel slag as a substitute of natural gravel aggregate. Testing physical and mechanical properties of nontraditional concrete with steel slag as a substitute for natural aggregates of 4/8 mm and 8/16 mm fractions confirmed the possibility of using slag as a partial replacement of natural aggregate. Several samples of concrete with steel slag achieved even better mechanical parameters (e.g., compressive strength, frost resistance) than samples with natural aggregate. Moreover, a life cycle assessment (LCA) was performed within the system boundaries cradle-to-gate. The LCA results showed that replacements of natural aggregates significantly affected the utilization rate of nonrenewable raw materials and reduced the overall negative impacts of concrete on the environment up to 7%. The sustainability indicators (SUI), which considered the LCA data together with the technical parameters of concrete, were set to evaluate sustainability of the analyzed concretes. Based on the SUI results, replacing only one fraction of natural gravel aggregate in concrete was a more sustainable solution than replacing both fractions at once. These results confirmed the benefits of using waste to produce sustainable materials in construction industry.

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Physical Properties of Mineral and Recycled Aggregates Used to Mineral-Asphalt Mixtures

Materials ◽

10.3390/ma12203437 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3437 ◽

Cited By ~ 2

Author(s):

Wojciech Andrzejuk ◽

Danuta Barnat-Hunek ◽

Jacek Góra

Keyword(s):

Raw Materials ◽

Physical And Mechanical Properties ◽

Asphalt Mixtures ◽

Recycled Aggregates ◽

Chemical Components ◽

Test Results ◽

Eds Analysis ◽

Road Surfaces ◽

Microstructure Examination

This article presents test results and examines the possibilities of using aggregate from ceramic waste for mineral-asphalt mixtures. In addition, the mineral composition, physical and mechanical properties of aggregates from natural raw materials such as dolomite, granodiorite and waste ceramic aggregate (introduced as a partial substitute for the main aggregate) were analyzed. The shape of grains was examined by determining the shape and flatness index of aggregates, resistance to grinding and frost resistance. The tested properties have a direct impact on the durability of road surfaces. To this end, the adhesion of asphalt to the surface of the aggregates used was additionally determined. Determination of surface roughness and two-dimensional (2D) topography of tested aggregates was carried out. The aggregates microstructure examination, coupled with the energy-dispersive X-ray spectroscopy (EDS) analysis, was conducted to determine the morphology and texture of the aggregates as well as to identify the basic chemical components.

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Determination of Combined and Second Order Factor Effects for Simultaneous Optimization of Physical and Mechanical Properties of NR/BR Blend System

Tire Science and Technology ◽

10.2346/tire.14.420404 ◽

2014 ◽

Vol 42 (4) ◽

pp. 290-304

Author(s):

Rajarajan Aiyengar ◽

Jyoti Divecha

Keyword(s):

Physical And Mechanical Properties ◽

Second Order ◽

Simultaneous Optimization ◽

Order Effects ◽

Elongation At Break ◽

Five Factors ◽

Rubber Compounds ◽

Polybutadiene Rubber ◽

Contour Plots

ABSTRACT The blends of natural rubber (NR), polybutadiene rubber (BR), and other forms of rubbers are widely used for enhancing the mechanical and physical properties of rubber compounds. Lots of work has been done in conditioning and mixing of NR/BR blends to improve the properties of its rubber compounds and end products such as tire tread. This article employs response surface methodology designed experiments in five factors; high abrasion furnace carbon black (N 330), aromatic oil, NR/BR ratio, sulfur, and N-oxydiethylene-2-benzothiazole sulfenamide for determination of combined and second order effects of the significant factors leading to simultaneous optimization of the NR/BR blend system. One of the overall optimum of eight properties existed at carbon 44 phr, oil 6.1 phr, NR/BR 78/22 phr with the following values of properties: tensile strength (22 MPa), elongation at break (528%), tear resistance (30 kg/mm), rebound resilience (67%), moderate hardness (68 International rubber hardness degrees) with low heat buildup (17 °C), permanent set (12%), and abrasion loss (57 mm3). More optimum combinations can easily be determined from the NR/BR blend system models contour plots.

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Basic set of experiments for determination of mechanical properties of sand

Bulletin of the Polish Academy of Sciences Technical Sciences ◽

10.2478/bpasts-2014-0015 ◽

2014 ◽

Vol 62 (1) ◽

pp. 129-137

Author(s):

A. Sawicki ◽

J. Mierczyński

Keyword(s):

Mechanical Properties ◽

Soil Mechanics ◽

Physical And Mechanical Properties ◽

Local Strain ◽

Initial State ◽

Laboratory Equipment ◽

Additional Information ◽

Basic Set ◽

Initial Anisotropy

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.

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