scholarly journals Ilmenite Mud Waste as an Additive for Frost Resistance in Sustainable Concrete

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2904 ◽  
Author(s):  
Filip Chyliński ◽  
Krzysztof Kuczyński
Keyword(s):  
Titanium Dioxide ◽  
Fly Ash ◽  
Frost Resistance ◽  
Building Materials ◽  
Industrial Wastes ◽  
Cement Matrix ◽  
Freeze Thaw ◽  
Sustainable Concrete ◽  
Potential Risks ◽  
Air Void

Sustainable development leads to the production of building materials that are safer for the environment. One of the ways to achieve sustainability in materials is the addition of industrial wastes and by-products, especially to concrete. However, the addition of waste to concrete often decreases its durability and the scope of aggression of the environment in which the concrete is used has to be reduced. Making sustainable concrete, which is also durable in more aggressive environments, is rather difficult. This article presents the results of tests performed on concrete containing ilmenite mud waste from the production of titanium dioxide, which was exposed to frost aggression with and without de-icing salts. The results have shown that a sustainable and frost resistant concrete can be made. After 200 freeze–thaw cycles, the compressive strength of the tested concretes decreased by less than 4%. Concretes were highly resistant for scaling and after 112 freeze–thaw cycles in water with de-icing salt, the scaled mass was less than 0.02 kg/m2. The air void distribution has also been analyzed. The results suited the requirements for frost resistance concrete and were similar to those obtained for a reference concrete with fly ash. The examination of the microstructure using scanning electron microscopy (SEM) has not shown any potential risks that might affect the durability of concrete. Particles of waste were thoroughly combined in the binder and some of its constituents seem to be an active part of the cement matrix. Long-term tests of shrinkage (360 days) have not shown any excessive values that would differ from the reference concrete with fly ash. The presented results have shown that sustainable concrete containing ilmenite mud waste from the production of titanium dioxide might also be resistant to frost aggression.

scholarly journals Freeze–Thaw Resistance and Air-Void Analysis of Concrete with Recycled Glass–Pozzolan Using X-ray Micro-Tomography

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 154
Author(s):  
Marija Krstic ◽  
Julio F. Davalos ◽  
Emanuele Rossi ◽  
Stefan C. Figueiredo ◽  
Oguzhan Copuroglu
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
The United States ◽  
Adsorption Method ◽  
X Ray ◽  
Freeze Thaw ◽  
Void System ◽  
Spatial Parameters ◽  
Micro Tomography ◽  
Air Void

Recent studies have shown promising potential for using Glass Pozzolan (GP) as an alternative supplementary cementitious material (SCM) due to the scarcity of fly ash and slag in the United States. However, comprehensive studies on the freeze–thaw (FT) resistance and air void system of mixtures containing GP are lacking. Therefore, this study aimed to evaluate GP’s effect on FT resistance and characterize mixtures with different GP contents, both macro- and microscopically. In this study, six concrete mixes were considered: Three mixes with 20%, 30% and 40% GP as cement replacements and two other comparable mixes with 30% fly ash and 40% slag, as well as a mix with 100% Ordinary Portland cement (OPC) as a reference. Concrete samples were prepared, cured and tested according to the ASTM standards for accelerated FT resistance for 1000 cycles and corresponding dynamic modulus of elasticity (Ed). All the samples showed minimal deterioration and scaling and high F/T resistance with a durability factor of over 90%. The relationships among FT resistance parameters, air-pressured method measurements of fresh concretes and air void analysis parameters of hardened concretes were examined in this study. X-ray micro-tomography (micro-CT scan) was used to evaluate micro-cracks development after 1000 freeze–thaw cycles and to determine spatial parameters of air voids in the concretes. Pore structure properties obtained from mercury intrusion porosimetry (MIP) and N2 adsorption method showed refined pore structure for higher cement replacement with GP, indicating more gel formation (C-S-H) which was verified by thermogravimetric analysis (TGA).

scholarly journals Durability of Structural Lightweight Concrete with Sintered Fly Ash Aggregate

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4565 ◽  
Author(s):  
Lucyna Domagała
Keyword(s):  
Fly Ash ◽  
Moisture Content ◽  
Water Absorption ◽  
Water Permeability ◽  
Lightweight Concrete ◽  
Concrete Strength ◽  
Initial Moisture Content ◽  
Cement Matrix ◽  
Secondary Importance ◽  
Freeze Thaw

The aim of this study was to present the problem of durability of structural lightweight concrete made of a sintered fly ash aggregate. The issue of durability was researched for 12 concrete series in terms of their water absorption, water permeability, and freeze-thaw resistance. Additionally, the microstructure of several concretes was analyzed with a scanning electron microscope (SEM). In the durability research, the influences of the following parameters were taken into consideration: The initial moisture content of sintered fly ash (mc = 0, 17–18, and 24–25%); the aggregate grading (4/8 and 6/12 mm); and the water-cement ratio (w/c = 0.55 and 0.37). As a result of various compositions, the concretes revealed different properties. The density ranged from 1470 to 1920 kg/m3, and the corresponding strength ranged from 25.0 to 83.5 MPa. The durability research results of tested lightweight concretes showed that, despite considerably higher water absorption, a comparable water permeability and comparable or better freeze-thaw resistance in relation to normal-weight concrete may be present. Nevertheless, the fundamental requirement of lightweight concrete to achieve good durability requires the aggregate’s initial moisture content to be limited and a sufficiently tight cement matrix to be selected. The volume share of the cement matrix and aggregate, the cement content, and even the concrete strength are of secondary importance.

Effect of fine fly ash and calcium hydroxide on air void structure in very-early-strength latex-modified concrete

2015 ◽  
Vol 42 (10) ◽  
pp. 797-807
Author(s):  
Pangil Choi ◽  
Sung Il Jeon ◽  
Kyong-Ku Yun
Keyword(s):  
Fly Ash ◽  
Calcium Hydroxide ◽  
Bridge Decks ◽  
Time Frame ◽  
Early Age ◽  
Freeze Thaw ◽  
Void Structure ◽  
Early Strength ◽  
Air Void ◽  
Air Void Structure

Very-early-strength latex-modified concrete (VES-LMC) was developed for rapid repairs of distresses in concrete bridge decks and pavements, with the emphasis on early-age strength gain so that the repaired bridges and pavements can be opened to traffic within the time frame required in the specifications. However, there are two main concerns in the use of VES-LMC — early-age cracking and poor air void structure. The main objective of this study was to further improve VES-LMC to minimize early-age cracking and improve freeze–thaw durability, which included the use of fine fly ash (FFA) and calcium hydroxide (CH). Laboratory experiments were conducted on VES-LMC materials with cement replaced with FFA as well as CH, and various tests performed. Early-age drying shrinkages of VES-LMC containing both FFA and CH in the amounts evaluated in this study were smaller than that of VES-LMC with no replacements. It is expected that the use of FFA and CH in the range evaluated in this study will reduce the cracking potential of VES-LMC. Overall, the replacement of cement with FFA and CH improved the characteristics of entrained air void system, which will enhance the durability of VES-LMC against freeze–thaw damage. Scanning electron microscope and energy dispersive spectroscopy analysis indicate the primary mechanism of the generation of small sized air voids in concretes containing adequate amount of FFA and CH is the gas formation reaction between citric acid solutions and CH during concrete mixing. It is expected that the inclusion of adequate amounts of FFA and CH in VES-LMC will improve the performance of repaired bridge decks and pavements in terms of reduced cracking and improved freeze-thaw durability.

scholarly journals The Synergy between Bio-Aggregates and Industrial Waste in a Sustainable Cement Based Composite

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6158
Author(s):  
Cătălina Mihaela Grădinaru ◽  
Adrian Alexandru Șerbănoiu ◽  
Radu Muntean ◽  
Bogdan Vasile Șerbănoiu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Splitting Tensile Strength ◽  
Partial Replacement ◽  
Cement Matrix ◽  
Freeze Thaw ◽  
Corn Cobs ◽  
Study Results ◽  
Sunflower Stalks

The effects of the fly ash and of the sunflower stalks and corn cobs within a cement-matrix composite were studied under the aspects of density, compressive strength, splitting tensile strength, elasticity modulus, and resistance to repeated freeze-thaw cycles. In the research were developed 20 recipes of cement-based composite, including the reference composite. Fly ash was used as partial cement replacement (10, 20 and 30% by volume), and the vegetal aggregates made by corn cobs and sunflower stalks as partial replacement of the mineral aggregates (25 and 50% by volume). The study results revealed that a lightweight composite can be obtained with 50% of vegetal aggregates, and the fly ash, no matter its percentage, enhanced the compressive strength and splitting tensile strength of the compositions with 50% of sunflower aggregates and the freeze-thaw resistance of all compositions with sunflower stalks.

scholarly journals Strength, Fracture and Durability Characteristics of Ambient Cured Alkali—Activated Mortars Incorporating High Calcium Industrial Wastes and Powdered Reagents

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1167
Author(s):  
Dhruv Sood ◽  
Khandaker M. A. Hossain
Keyword(s):  
Elastic Modulus ◽  
Fly Ash ◽  
Calcium Hydroxide ◽  
Ultrasonic Pulse ◽  
Industrial Wastes ◽  
Freeze Thaw ◽  
High Calcium ◽  
Alkali Activated ◽  
Ambient Curing ◽  
Class F

Alkali-activated mortars (AAMs) are developed incorporating binary/ternary combinations of industrial wastes comprising of fly ash class C (FA-C), fly ash class F (FA-F) and ground granulated blast furnace slag (GGBFS) with alkaline reagents and silica sand. The use of high calcium precursors, calcium-based powder form reagents, dry mixing method, and ambient curing with performance characterization based on chemical ratios and fracture properties are some novel aspects of the study. The mechanical (dry density, compressive strength, ultrasonic pulse velocity, elastic modulus, fracture/crack tip toughness and fracture energy), durability (shrinkage/expansion and mass change in water and ambient curing conditions, water absorption and freeze-thaw resistance) and microstructural (SEM/EDS and XRD analyses) characteristics of eight AAMs are investigated. The binary (FA-C + GGBFS) mortars obtained higher compressive strengths (between 35 MPa and 42.6 MPa), dry densities (between 2032 kg/m3 and 2088 kg/m3) and ultrasonic pulse velocities (between 3240 m/s and 4049 m/s) than their ternary (FA-C + FA-F + GGBFS) counterparts. The elastic modulus and fracture toughness for mortars incorporating reagent 2 (calcium hydroxide: sodium sulphate = 2.5:1) were up to 1.7 and five times higher than those with reagent 1 (calcium hydroxide: sodium metasilicate = 1:2.5). This can be attributed to the additional formation of C-S-H with C-A-S-H/N-C-A-S-H binding phases in mortars with reagent 2. Ternary mortars exhibited comparatively lower shrinkage/expansion and initial sorptivity indices than their binary counterparts due to the lower geopolymerisation potential of fly ash class F that facilitated the reduction of matrix porosity. All mortar specimens demonstrated 100% or more relative dynamic modulus of elasticity after 60 freeze-thaw cycles, indicating the damage recovery and satisfactory durability due to probable micro-level re-arrangement of the binding phases. This study confirmed the viability of producing cement-free AAMs with satisfactory mechanical and durability characteristics.

scholarly journals Investigation of thermal, moisture, and mechanical properties of wet and dry fired clay materials to assess frost damage risk

2019 ◽  
Vol 282 ◽  
pp. 02083
Author(s):  
Kazuma Fukui ◽  
Chiemi Iba ◽  
Madoka Taniguchi ◽  
Kouichi Takahashi ◽  
Daisuke Ogura
Keyword(s):  
Mechanical Properties ◽  
Environmental Conditions ◽  
Frost Resistance ◽  
Building Materials ◽  
Frost Damage ◽  
Thermal And Mechanical Properties ◽  
Freeze Thaw ◽  
Different Temperatures ◽  
Damage Risk ◽  
Clay Materials

Frost action is one of the main causes for deterioration of porous building materials under defined hygrothermal conditions. For an accurate assessment of the frost damage risk under various environmental conditions, thermal, moisture, and mechanical properties should be considered; the hygrothermal properties affect the distribution of temperature and amount of frozen water in the material, whereas the mechanical properties are necessary to predict deformation and damage. Moreover, the dependency of these properties on the moisture content should be understood. Therefore, in this study, thermal, moisture, and mechanical properties of wet and dry fired clay materials were measured. The fired clay materials were sintered at two different temperatures, 1000 °C and 1100 °C (samples T10 and T11, respectively) for comparison. The measured thermal and mechanical properties are considerably different in the wet state compared to the dry state. Freeze–thaw tests were conducted to investigate the relation between the material properties and the frost resistance under a simple experimental condition. As expected, based on the pore structure and obtained mechanical properties, T10 exhibited lower frost resistance than T11 in the freeze–thaw test. Finally, frost damage risk was assessed under various environmental conditions based on the obtained hygrothermal and mechanical properties.

The characteristics of air void and frost resistance of RCC with fly ash and expansive agent

2006 ◽  
Vol 20 (8) ◽  
pp. 586-590 ◽  
Author(s):  
Pei-wei Gao ◽  
Sheng-xing Wu ◽  
Ping-hua Lin ◽  
Zhong-ru Wu ◽  
Ming-shu Tang
Keyword(s):  
Fly Ash ◽  
Frost Resistance ◽  
Expansive Agent ◽  
Air Void

Durability of Concrete with Fly Ash from the Dam Orlík after 55 Years

2017 ◽  
Vol 1144 ◽  
pp. 81-87
Author(s):  
Ondřej Zobal ◽  
Pavel Reiterman ◽  
Tomáš Plachý ◽  
Zdeněk Bittnar
Keyword(s):  
Sustainable Development ◽  
Fly Ash ◽  
Frost Resistance ◽  
Building Materials ◽  
Current Issue ◽  
The Body ◽  
Important Data ◽  
Durability Of Concrete

The paper focuses on some properties of concrete with fly ash after 55 years in operation. Among other things this topic refers to still current issue of sustainable development. In this case, it is saving of cement by using of substitution of fly ash. Another researched topic in the paper is the durability of structures and building materials. For obtaining important data, samples of concrete were extracted from the body of the dam Orlík, which has been in operation since 1961 and fly ash was used in a mixture. The results of the measurement of carbonation and frost resistance of concrete with fly ash addition are presented and analyzed in this paper.

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