Influence of Mix Design Parameters on Geopolymer Mechanical Properties and Microstructure

2017 ◽  
pp. 21-33 ◽  
Author(s):  
Mukund Lahoti ◽  
En-Hua Yang ◽  
Kang Hai Tan
Keyword(s):  
Mechanical Properties ◽  
Mix Design ◽  
Design Parameters

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

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.

scholarly journals Use of industrial wastes as filler in open-graded friction courses

2017 ◽  
Vol 12 (2) ◽  
pp. 106-116 ◽  
Author(s):  
Rajan Choudhary ◽  
Dibyatonu Chattopadhyay ◽  
Abhinay Kumar ◽  
Ashok Julaganti
Keyword(s):  
Regression Analysis ◽  
Fly Ash ◽  
Course Design ◽  
Industrial Wastes ◽  
Mix Design ◽  
Design Parameters ◽  
Void Content ◽  
Filler Materials ◽  
Open Graded Friction Course ◽  
Marble Dust

For a fast developing economy like India, expansion, rehabilitation, and maintenance of transportation infrastructure is crucial and require huge quantities of high quality natural aggregates. Meanwhile, vast amounts of industrial wastes accumulating in the country pose problems related to safe and sustainable disposal. The present study investigated possible utilisation of marble dust, a waste from stone industry, and fly ash, a waste from thermal power stations, as filler materials in open-graded friction course mixes. Open-graded friction course mixes incorporating fly ash, marble dust, and two sources of stone dust as filler fractions were designed and evaluated for mix design properties including draindown, abrasion loss, air void content, and permeability. Morphology of each filler was characterised through scanning electron microscopy. Physicochemical properties of fillers were examined through Rigden voids, German filler test, methylene blue, and hydrometer analysis. Analysis of variance using Fisher multiple comparison procedure was performed to evaluate the effect of filler type on design properties of open-graded friction course mixes. Regression analysis using forward selection technique was performed to identify significant filler characteristics influencing open-graded friction course properties. Results showed that filler type affected open-graded friction course design parameters significantly. Open-graded friction course mixes with marble dust showed promising performance with lowest draindown, and highest durability, air voids, and permeability. Regression analysis identified Rigden void content of filler materials as a major filler characteristic affecting the mix design parameters of open-graded friction course mixes.

Earth-Based Mortars: Mix Design, Mechanical Characterization and Environmental Performance Assessment

2022 ◽  
Author(s):  
Rayane de Lima Moura Paiva ◽  
Adriana Paiva Souza Martins ◽  
Lucas Rosse Caldas ◽  
Oscar A.M. Reales ◽  
Romildo Dias Toledo Filho
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Environmental Impacts ◽  
Calcium Chloride ◽  
Clay Fraction ◽  
Supplementary Cementitious Materials ◽  
Mix Design ◽  
Partial Replacement ◽  
Promising Alternative ◽  
The Earth

The incorporation of sustainable materials in the civil construction sector has grown in recent years to minimize environmental impacts. Among these materials, the use of earth, a local raw material that does not require much energy for its processing, appears as an advantageous and promising alternative. Earth mortars stabilized with natural binders, when compared to conventional mortars, can have technological, economic and environmental advantages. The objective of this work was to develop an earth-based mortar stabilized with mineral binders using a 1:3 binder to aggregate mass proportion, and to evaluate its fresh and hardened state properties, as well as its environmental impacts using Life Cycle Assessment (LCA) with a cradle to gate scope. The selected materials were divided in four groups: (i) cement, hydrated lime, fly ash and metakaolinite (binders), (ii) natural sand and coarse fraction of the earth (aggregates), (iii) calcium chloride and superplasticizer (additives) and (iv) water. In the matrix formulation the clay fraction from earth constituted the majority of the binder. The selection of supplementary cementitious materials as additional binders provided improvements in workability and mechanical properties of the mortar. A mix design was carried out using different cement (5; 7.5 and 10%) and fly ash (11; 13.5 and 16%) mass percentages. The water/binder material ratio, superplasticizer content and calcium chloride content were 0.65; 2% and 1%, respectively. The results showed that an increase in fly ash content combined with a decrease in cement content provided an increase in workability and a decrease in mechanical properties of mortars. Nevertheless, the mechanical performance of the mortars remained above the minimum values prescribed in Brazilian construction codes. From the results analysis it was concluded that partial replacement of cement by fly ash provided greater workability in the fresh state and reduced the environmental impacts of the earth-based mortar.

scholarly journals Predicting the Mechanical Properties of Bimrocks with High Rock Block Proportions Based on Resonance Testing Technology and Damage Theory

2019 ◽  
Vol 9 (17) ◽  
pp. 3537
Author(s):  
Yuexiang Lin ◽  
Limin Peng ◽  
Mingfeng Lei ◽  
Xiang Wang ◽  
Chengyong Cao
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Constitutive Model ◽  
Uniaxial Compression ◽  
Rock Block ◽  
Dynamic Elastic Modulus ◽  
Parameter Determination ◽  
Design Parameters ◽  
Damage Theory ◽  
Design And Construction

Block-in-matrix-rocks (bimrocks) are very complicated geological masses that cause many challenging problems during the design and construction of engineering projects, such as parameter determination and landsliding. Successful engineering design and construction depends on a suitable constitutive model and reliable design parameters for geological masses. In this paper, the vibration attenuation signal of welded bimrocks was obtained and studied using resonance test technology. Combined with a uniaxial compression test, a constitutive model was proposed to describe the mechanical behavior of welded bimrocks. On this basis, the relations between the dynamic elastic modulus and the physical parameters of bimrocks were established, which included macroscopic mechanical parameters and damage constitutive parameters. Consequently, a new technological process was proposed to provide quick identification of the mechanical properties of welded bimrocks. The results indicate that the dynamic elastic modulus is highly correlated with the rock block proportion (RBP) and uniaxial compression strength (UCS). It is an effective parameter to predict the strength of the bimrocks with high RBPs. Additionally, the proposed constitutive model, which is based on damage theory, can accurately simulate the strain softening behavior of the bimrocks. Combining the resonant frequency technology and the proposed constitutive model, the complete stress strain curve can be obtained in a rapid and accurate manner, which provides a further guarantee of the stability and safety of underground engineering.

Microscopic Analysis and Study of High-Performance Seawater All-Coral Concrete

2019 ◽  
Vol 815 ◽  
pp. 216-222
Author(s):  
Chao Chen ◽  
Jin Ming Liu ◽  
Yang Yang ◽  
Zhi Guo Guo
Keyword(s):  
Mechanical Properties ◽  
Natural Environment ◽  
High Performance ◽  
Work Performance ◽  
Room Temperature ◽  
Microscopic Analysis ◽  
Internal Curing ◽  
Mix Design ◽  
Binder Ratio ◽  
Water To Binder Ratio

The ocean islands are far from inland and the concrete sandstone aggregates are scarce. In this paper, high-performance seawater all-coral concrete was developed by seawater mixing and room temperature maintenance design, and by optimizing the water-to-binder ratio, regulating internal curing, changing auxiliary cementing materials and blending ratio, incorporating expansion agent, adjusting fiber blending, etc. Combined with the consideration of work performance and mechanical properties, the concrete self-shrinkage is adjusted to further optimize the mix design. The mechanical properties of the optimized high-performance seawater all-coral concrete were studied, and the relevant durability tests were carried out according to the natural environment characteristics of the island. This is of great significance to the construction of island projects, repair and construction, and construction of protective projects [1].

scholarly journals Properties of pre-cast terrazzo tiles and recommended specifications

Cerâmica ◽  
2009 ◽  
Vol 55 (333) ◽  
pp. 84-87
Author(s):  
G. Karam ◽  
M. Tabbara
Keyword(s):  
Mechanical Properties ◽  
Quality Control ◽  
Physical And Mechanical Properties ◽  
Control Measures ◽  
Mix Design ◽  
Experimental Program ◽  
Index Test ◽  
Basic Reference ◽  
Casting Pressure ◽  
Simple Surface

A targeted experimental program was carried out to establish basic reference physical and mechanical properties of commercially available pre-cast marble chip terrazzo tiles and to investigate the effects of varying manufacturing process parameters on those properties. The transverse strength, density, water absorption, and abrasion resistance were measured as a function of casting pressure and residence time in the casting mold for a standard mix design. A simple surface abrasion index test was developed and applied comparing pre-cast terrazzo tiles with reference natural tiling stones. Recommendations for improving existing specifications and developing quality control measures are presented.

Development of Photocatalytic Pervious Concrete Pavement for Air and Storm Water Improvements

2012 ◽  
Vol 2290 (1) ◽  
pp. 161-167 ◽  
Author(s):  
Somayeh Asadi ◽  
Marwa M. Hassan ◽  
John T. Kevern ◽  
Tyson D. Rupnow
Keyword(s):  
Flow Rate ◽  
Mechanical Performance ◽  
Concrete Pavement ◽  
Pervious Concrete ◽  
Mix Design ◽  
Unit Weight ◽  
Experimental Program ◽  
Design Parameters ◽  
Operational Parameters ◽  
Cleaning Agents

Self-cleaning, air-purifying pervious concrete pavement is a promising technology that can be constructed with air-cleaning agents with superhydrophilic photocatalyst capabilities, such as titanium dioxide. Although this technology has the potential of supporting environment-friendly road infrastructure, its effectiveness depends on a number of design and operational parameters that need to be evaluated. The objective of this study was to evaluate the mechanical, environmental, and mix design parameters that influence the performance and effectiveness of photocatalytic pervious concrete pavement. To achieve this objective, an experimental program was conducted in which the effects of relative humidity level, pollutants' flow rate, and mix design parameters, including void ratio and depth of the photocatalytic layer, were investigated. Mechanical performance tests included porosity, unit weight, permeability, and compressive strength. The environmental efficiency of the samples to remove nitrogen oxides (NOx) from the atmosphere was measured in the laboratory. Results of the experimental program showed that increasing the depth of the photocatalytic layer increased NOx reduction efficiency. In addition, NOx removal efficiency decreased with the increase in the pollutant flow rate and increased with the increase in ultraviolet light intensity.

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