The 10 most-cited articles in Advanced materials research, 2018

Facing the cement and concrete development process, reducing greenhouse gases and the consumption of natural resources has become an important issue. To reduce the cement content in concrete, the increased use of concrete combining large amounts of industrial by-products is expected. Ground granulated blast furnace slag (GGBFS) has been used as a supplementary cementitious material in ordinary Portland cement (OPC) concrete. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40%, and 60% by weight were used to produce concrete. Compressive strength test, water absorption, electrical resistivity, and rapid chloride penetration test (RCPT) were performed to investigate the effect of GGBFS on compressive strength and durability of concrete. Test results show that GGBFS concrete with 40% cement replacement (G40) has the highest compressive strength. The water absorption and chloride permeability reduced with the increasing cement replacement percentage by GGBFS. Meanwhile, the electrical resistivity increased with an increasing GGBFS replacement percentage. Based on…

Sugarcane bagasse is an agricultural waste that is potentially used as natural silica resources. Natural silica claimed to be safe in handing, cheap and can be generate from cheap resource. In the objectives of this study were to prepared silica from Sugarcane bagasse. The preparation of Sugarcane bagasse ash by burning at 700 °C for 4 and 6 h, respectively in atmosphere. The result of X-ray florescent: XRF, silica content which was obtained after heat treatment at 700 °C for 6 h was 80.814 wt%. Bagasse ash was purified by alkaline extraction method with 1.5, 2 and 2.5 N sodium hydroxide (NaOH), respectively. And refluxed by using concentrated 2 N sulfuric acid. From X-ray diffraction pattern showed that the obtained products were amorphous silica, 2.5 N sodium hydroxide. The morphology was observed by SEM, sphere and average particles dimension of synthesis silica with 1.5, 2 and 2.5 N NaOH are 120, 100 and 80 nm respectively. The SEM micrographs showed that the Concentration of NaOH was increased, the particles dimension decreased

Smart surfaces and materials can play a significant role in intelligent, adaptive and responsive envelopes because of these intrinsic properties. The environmental question and energy efficiency in which the construction sector is involved, is in a process that can not be interrupted and that puts researchers and designers in front of a scientific and design challenge in which it is necessary to contribute to find different ways of study and experimentation on new materials and constructive languages, ranging from the application, to the structural, design and molecular, to mention the main ones. The development of technologies is helping architects of the “biomimetic current” to recreate complex structures that can be found in nature, using innovative construction methods and materials. In this paper, some existing biomimetic design strategies applied for nature emulation are presented with the aim to understand the contribution of biomimetic materials to the design culture. Case studies show the diversity of possible applications of natural phenomena in architecture with the aim…

Advancements in computational tools are offering designers the possibility to change their relationship with materials and establishing new synergies between matter, form and behaviour. This work explores this paradigm by introducing the use of auxetic metamaterials, specifically engineered to obtain properties beyond those found in nature, to generate structures with adaptive curvature obtained from planar construction elements. It is discussed how through programming an initial geometry with the strategic negotiation of several geometrical parameters it is possible to control finely the structural and morphological features of a structure. The paper presents approach, tools and methods for designing auxetics for large scale applications, and use them to create heterogeneous active-bending structures.

Deformation due to load from the construction of infrastructure in soft ground is high and sometimes also becomes problematic. There are various techniques to strengthen the ground among which, the most suitable and commonly used method is chemical stabilization using cement. This method is fast and cement is relatively cheap, abundant and efficient. This research is focused on the study of improvement on physical and mechanical properties of cement mixed clay. Soil sample from Kathmandu, Nepal is taken for the laboratory investigations. The soil is reconstituted by using Ordinary Portland Cement of 5%, 10%, and 15% by its mass. The study revealed that physical and mechanical characteristics of cemented clay are greatly improved for engineering purposes. The specific gravity of all samples are linearly vary with cement content. Similarly, the liquid limit and plastic limit of clay are increased with increased cement content. However, hydraulic conductivity of the soils is decreased with the increase in cement content i.e. reduction is almost 7.5 times when cement increases from 5%…

The present work deals with the optimization of micro-WEDM process parameters for machining Ti49.4-Ni50.6 shape memory alloy (SMA) for orthopedic implant application. Effect of micro-WEDM parameters viz. Gap voltage, capacitance, wire feed and wire tension on the response variables such as material removal rate, surface roughness, kerf width and dimensional deviation is determined. As Ti-Ni SMA has fascinating properties and bio-compatibility, have been considered for present work. Nine experiments have been performed on micro-WEDM based on an orthogonal array of Taguchi method. Subsequently, the grey relational analysis (GRA) method is applied to determine an optimal set of process parameters. It is observed that optimized set of parameters A3B3C3D1 viz. 140 V gap voltage, 0.4 µF capacitance, wire feed 30 µm/sec and 30% of wire tension determined by using GRA offers maximum MRR and minimum SR, KW and DD. From the Analysis of Variance, it is seen that the process parameter capacitance is the most significant parameter for multi-response optimization with a percentage contribution of…

An original experimental campaign never conducted until now on Non-Hazardous Waste Incineration aggregates is presented in this paper. The experiments were conducted in two phases: Scanning Electron Microscopy (SEM) and instrumented indentation. A cartography followed by a series of Quantitative Chemical Microanalysis (QCM) was carried out on the 0/12.5 mm fraction of the particle size distribution. Instrumented indentation tests were carried out on isolated particles of 25 mm in diameter. Observations at the SEM yielded the exact chemical composition of the bottom ashes. It has been found that the proportions of the chemical elements composing the material are slightly different from those of other studies. This difference has made it possible to note that the zone of production of the bottom ash significantly influences their physicochemical characteristics. From the indentation curves obtained, the “Olivier and Pharr” method was used to determine the reduced modulus of elasticity “Er”. Mean values of approximately 65 GPa and 40 GPa were obtained respectively for vitreous phases…

With the rapid development of construction, the high quality of the construction material is required. Mixing carbon fiber in concrete attracts more and more attention as it can reinforce concrete. However, the science research and engineering application of carbon fiber reinforced concrete is relatively few. In this paper, the effects of different mixing amount of carbon fiber and the sand ratio in concrete and the curing time of concrete and relationships between these factors were investigated. Proper carbon fiber and sand ratio can promote the compressive strength of concrete and it has a good resistance to cracking. The compressive strength of concrete with different mixing amounts of carbon fiber peaks when the sand ratio was 31% and the compressive strength was better when the carbon fiber mixing amount was 0.2% and 1% than any other ratios after 28 days. When the sand ratio was 31%, the compressive strength of carbon fiber mixing amount increased with the increase of curing time and it reached the top when the carbon fiber ratio was 0.8%. The mixing amount of carbon fiber…

Micro Arc Oxidation (MAO) coating was performed on Al-2014 aluminium alloy in aqueous solution of silicate, phosphate and hybrid electrolytic environments. The MAO thickness was measured around 5-15 μm, in which significant thickness of both dense and porous layers were identified. A combination of nanocrystalline α-Al2O3and Υ-Al2O3 was identified in the MAO coating using X-ray diffraction analysis. The thickness and morphology of the coating, which is analyzed using SEM are different for different MAO process parameters and it was found that the MAO coating prepared in phosphate electrolyte is giving a better coating with higher coating thickness, minor pore size and better adherence.

The objective of the paper is to present the newest results of our complex research work. In order to determination and comparison of the fatigue resistance, fatigue crack growth tests were performed on different grades of S690QL quenched and tempered, and S960TM thermomechanically rolled high strength steels. 15 mm and 30 mm thick base materials were used for our investigations. Welded joints were made from these base materials, using gas metal arc welding with matching, overmatching, and undermatching filler metals. In the paper, the performance of the welding experiments will be presented, especially with the difficulties of the filler material selection; along with the results of the fatigue crack growth examinations executed on the base materials and its welded joints. Statistical aspects were applied both for the presenting of the possible locations of the cracks in the base materials and the welded joints and for the processing of the measured data. Furthermore, the results will be compared with each other, and the possibility of derivation of fatigue crack propagation limit…