Université Mouloud Mammeri de Tizi Ouzou (UMMTO): Research Review of Sciences and Technologies
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Performance evaluation and statistical analysis of saw dust as concrete
Get PDFThe utilization of industrial by products instead of the cementitious materials in concrete leads to sustainable environment and helps to reduce the environmental pollution. This part of the research concentrates on the performance evaluation of Saw Dust Ash (SDA) as a partial replacement for cement as well as the regression analysis among different parameters. It includes the setting time, fresh concrete properties and hardened concrete properties of the saw dust ash concrete. SDA was used by weight from 5% to 20% in steps of 5% to replace ordinary Portland cement. The fresh concrete properties indicate that the workability of SDA concrete decreases as the percentage replacement of SDA increases. The compressive strength, flexural and split tensile strength of the hardened concrete increases up to 10% of saw dust ash and then decreases. It is concluded that the optimum percentage to replace cement with saw dust ash is up to 10% for the reliable results. Further replacement would be detrimental to the strength of the concrete. The regression analyses to predict split tensile strength and flexural strength with respect to compressive strength shows very good correlation with regression coefficients of 0.979 and 0.911 respectively. The saw dust ash concrete was also found to be cheaper and friendlier to the environment than Portland cement concrete in the proportion to the percentage of cement replaced
3-D Move Mechanistic Analysis and Cost Effectiveness of Asphalt Rubber and Polymer Modified Asphalt Pavement Under Various Axle Loading Conditions
Get PDFA variety of axle loading conditions can lead to different tensile strains in asphalt pavements. One way to increase resistance to these tensile strains is to add materials such as crumb rubber or polymers to the pavement mixture. Using three given asphalt pavement design mixtures, a 3D-Move mechanistic analysis was performed to determine the fatigue life of three given mixtures: unmodified reference, asphalt rubber, and polymer modified. These mixtures were tested under various axle loading conditions. This mechanistic analysis was then combined with a cost analysis which showed that despite the increase in cost, the asphalt rubber design mixture was the most cost-effective, with the polymer modified mixture finishing in second ahead of the unmodified reference mixture.
Study on the Use of Construction and Demolition Waste for Road Base or Subbase Pavement Construction in Hanoi
Get PDFReuse or recycling of construction and demolition waste (CDW) has become an inevitable trend in the world. Currently, the amount of CDW generated in Hanoi is estimated at more than 4,000 tons per day, of which only about 30% has been controlled and recycled. The CDW comes from many different sources such as construction, repair, renovation, demolition of houses, residential buildings, public buildings, transportation infrastructure works, etc... The CDW commonly comprises soil, bricks, mortar and concrete, and has been reused in many applications around the world. In Vietnam, there are also some research programs set up for reutilizing the material, however, has not been concretely applied in practice. In order to consider the applicability of CDW in road construction, an experimental program was conducted using CDW as the aggregate for the cement treated grain material base layer in road pavement structure. The weight ratios of cement used in the mixture were 4%, 5%, 6%, 7% and 8%. The test results showed that the main mechanical properties of compressive strength, split tensile strength and elastic modulus of the mixture, increased proportionally with the cement content in the mixture
Experimental Study of Using Paper Production Industry Waste as Soil Stabilizer for Road Construction in Vietnam
Get PDFThe solution of using organic and inorganic chemical agents to strengthen loading capacity of soil for base, subbase or surface layers in unpaved road pavement has been applied for a long time in the world. In Vietnam, the method has been applied with conventional such as lime, cement, fly ash, or bitumen. Since the years of 2000s, the new soil stabilizers have been introduced to Vietnam. However, the price of the imported admixtures is still the barrier for practical applications. DBS-06 is a domestic lignosulfonate soil stabilizer synthesized from the paper industry waste, which was collected from the HoaBinh paper factory located in Ky Son District, HoaBinh Province. The study program was conducted to investigate the main mechanical properties of the soil specimens stabilized by DBS-06intending for used in road construction. The test results showed that the soil treated with DBS-06 was significantly improved the strength of compression, split tensile and elastic modulus, the three critical indicators representing forload bearing capacity of the material, in both normal and water saturated conditions
Assessing the mechanical behaviour of adobe masonry under uniaxial compressive strength.
Get PDFEarth building has always existed on all continents; it constitutes an integral part of the cultural heritage of mankind. The present study is particularly interested in the valorisation of adobe masonry. To do this, a series of adobe units (three types: a, b and c) and adobe masonry wallets (A, B, and C) were prepared manually and infilled with 1cm thick earth mortar. In order to study the mechanical behaviour of the wallets in the laboratory, we study the mechanical behaviour of adobes and earth mortar then we apply the uniaxial loading method on the wallets. Also we present a new analytical formula which gives the mechanical properties of wallets derived from those of bricks and mortar that were determined before they were assembled. The experimental study shows that the compressive strength of wallets is 33% lower than that of adobes, and the deformations are similar to those of bricks, but they are 6 to 8 times smaller than those of mortar. The experimental mechanical properties of wallets were compared with those determined analytically. It give us results similar to the experimental ones with a ratio EManal/ EMexp equal to 1.2
Comparative study of mechanical and structural properties of three different grades of purity of commercial aluminium
Get PDFThe influence of three grades of purity of commercial aluminium on the evolution of the major mechanical characteristics: stress and strain energy, hardness, elongation and stress coefficients, resilience and microstructure have been studied. It was found that the first resistance parameters decrease with the increase in the degree of purity of the chosen material to the disadvantage of the ductility characteristics which rise for the considered states. Furthermore, it is important to note that strain-hardening and annealing lead to considerable hardening and softening respectively. The latter can be respectively associated with an increase in the density of the dislocations and the movement of impurity elements towards the dislocations
An Appraisal on the Parameters Influencing Lime Stabilization of Soils
Get PDFSoil stabilization is a common engineering technique used to improve the physical properties of weak soil in order to achieve the desired engineering requirements. Among the various chemical stabilization techniques adopted for expansive soils, lime stabilization is the most widely adopted for controlling the swell-shrink properties of expansive soils. This study reviews the major research works carried out in the application of lime stabilization and attempts to understand various parameters that influence the effectiveness of lime stabilization. The different parameters that have been discussed include Soil Type and Mineralogy, Type, Quantity and Quality of Lime, Curing Period, Type of Curing, Curing Temperature, Moulding / Placement Water Content, Pulverization Quality, Strain Rate, pH, Organic Content, Sulphates and Extreme Conditions
Editorial
No full textThis special issue of Journal of Materials and Engineering Structures (JMES) includes manuscripts of some of the presentations at the Forth International Conference on Sustainability in Civil Engineering (ICSCE 2022), held during 25-27 November, 2023 at Hanoi, Vietnam. We believe that all the papers published in this special issue will be an opportunity for researchers to present recent works on Sustainability in Civil Engineering field.The International Conference on Sustainability in Civil Engineering is very significant to the development of new ideas and the promotion of research into advanced in Sustainability in Civil Engineering field. ICSCE 2022 received more than 220 abstracts and 162 full papers from 14 countries and 120 full papers were accepted. According to their subject and their merit by professionals, twenty-five of the best papers presented at the ICSCE 2022 Conference have been rigorously reviewed before being accepted for this special issue.The first paper is a keynote speaker. It focuses on resource recycling, low carbon emissions, and environmental safety as means to building a sustainable environment in order to reinforce concrete works, particularly in civil engineering buildings.Six interesting articles deal with works of art and particularly bridges. Methods for detecting structural damage as part of monitoring during the operating phase are thus presented. Other methods for analyzing the delayed or dynamic responses of bridges are also covered.Five articles in this issue deal with the theme of road operation, monitoring their condition, as well as the use of construction waste or industrial waste in the construction of new roads.Five articles deal with the theme related to transport infrastructures such as railways and tunnels.Some of the other papers deal with the subject of durability relating to different themes of civil engineering, such as the performance of concrete reinforced with ash-based Geopolymer, GFRP rebars, fly ash and recycled concrete aggregate by cement.We thank all of the authors who contributed to this special issue. You can find below the important information on the forth International Conference on Sustainability in Civil Engineering such as the aim and scope and the main topics of the ICSCE2022
Assessment of blasted excavation inaccuracy at tunnel face and influences on tunnelling effectiveness
Get PDFBlasting has been the most effective solution for tunnel excavation in hard rock. The accuracy of the blasting works is demonstrated by the similarity between the design and the actual excavation boundary. Hence, the overbreak and underbreak of the tunnel boundary are used to evaluate the tunnel excavation. Widely applied for rock tunnelling, New Austrian Tunnelling Method (NATM) has been used for almost all highway tunnels in Vietnam. The assessment of the previous projects is essential since it provides learnt experiences and enriches the knowledge to handle the tunnelling technology. With this aim, the paper studied the case of a 500m NATM tunnel located on the N01 national highway in Central Vietnam. The practical excavation zone was examined, and the overbreak and underbreak of the tunnel boundary during the excavation by explosive was investigated. The dependences of the overbreak and underbreak on the geological and technical conditions were indicated. The tunnelling effectiveness was then assessed through the additional materials and works for the face correction activities
Dissemination of technic for concrete using low-quality recycled aggregate to achieve a sustainable environment: examination on design method and validity of recycled aggregate concrete
Get PDFMany resources are used in the concrete-related sector to construct civil engineering buildings. Therefore, using the various by-products for resource circulation throughout the lifecycle of the concrete-related sector is critical to building a sustainable society. This study focuses on resource recycling, low carbon emissions, and environmental safety as means to building a sustainable environment in order to reinforce concrete works, particularly in civil engineering buildings. It also presents the examination results of the design method and validity for the active use of low-quality recycled aggregate concrete to decrease waste generation, reduce CO2 emissions, and ensure environmental safety. Consequently, it was confirmed that the water–cement ratio could be set on the basis of safety reasons for the production of recycled aggregate concrete-Class M using the aggregate replacement method at all ready-mixed concrete factories. This was achieved by employing the strength reduction ratio obtained from the difference between the relative water absorption of normal-weight concrete and that of recycled aggregate concrete