Browsing by Author "Senhadji, Y."

Now showing 1 - 4 of 4

Durability Of Natural Pozzolan-based Mortar Exposed To Sulfate Attack
(University of Eloued جامعة الوادي, 2016-05-01) Laoufi, L.; Senhadji, Y.; Benazzouk, A.; Langlet, T.; Mouli, M.; Laoufi, I.
Cement is a strategic commodity in the civil engineering for the construction of reinforced concrete structures. But its production generates around 5% of toxic gases such as CO2 responsible for environmental degradation. Furthermore, cement industry is a consumer sector of non-renewable energy. The use in the cement of natural additions is a solution to reduce the CO2 gas and the cost of production. The purpose of this work is the study of a sustainable building material: natural pozzolan Beni-saf (PNB) incorporated to mortars exposed to sulfate attack (5% Na2SO4). The loss of mass, monitoring the pH reading of each attack solution as well as specimens dimensions are different tests to study the durability of mortars made with 10, 20 and 30% of natural pozzolan. The result derived from this research is that pozzolan improves mortars resistance to sodium sulfate environment.
The Effect Of High Temperatures On Concrete Incorporating Ultrafine Silica And Polypropylene Fibers
(University of Eloued جامعة الوادي, 2016-05-01) Benkaddour, M.; Senhadji, Y.; Kazi Aoual, F.; Semcha, A.
In recent years, lots of studies have attempted to examine the possible causes for the thermal instability of ordinary concrete and high performance. However, we still do not know the exact terms of phenomena taking place during exposure to high temperature and the technological solutions that exist (polypropylene fibres, thermal reported) are not always well controlled. In this work, several concrete formulations have been tested and multi-scale observation of high-temperature behavior of ordinary concrete (compressive strength of 48 MPa) and HPC (compressive strength 75 MPa) were adopted. On the scale of the material, the identification of trends with temperature data such as porosity and particularly the mechanical properties allow us to better understand the behaviour of concrete at high temperature differential thermal analysis have been also made.
The Evolution Of Shrinkage Strain Of Pet-mortar Composite Eco-materials
(University of Eloued جامعة الوادي, 2017-01-01) Chaib, O.; Benosman, A. S.; Kazi Tani, N.; Senhadji, Y.; Mouli, M.; Taïbi, H.; Hamadache, M.
Concretes and mortars are subjected to several kinds of shrinkage strains which represent the volumic variations resulting from the cement hydration and are governed by various physical and chemical aspects. The use of polyethylene terephthalate PET plastic wastes which are available in quantity and within low cost in our country yields a very important economic and environmental impact in the construction industry. Thus, we are interested to investigate the effect of PET volumetric additive amounts for cement substituting and for the behavior of the total, drying and autogenous shrinkage. Comparison study of obtained experimental results with codale prediction models were performed according to Eurocode 2 (EC2) in order to analyze the evolution of shrinkage strain with PET-mortar composite ages and for several rates of PET waste additions. According to obtained results, PET additions acts to reduce shrinkage strains of PET-mortar composites which promote the use of these modified mortar Eco-materials in the field of construction industry.
Mortar Incorporating Supplementary Cementitious Materials: Strength, Isothermal Calorimetry And Acids Attack
(University of Eloued جامعة الوادي, 2016-05-01) Senhadji, Y.; Benosman, A.s.; Escadeillas, G.; Mouli, M.; Laoufi, L.; Khelafi, H.
Supplementary cementitious materials (SCMs) prove to be effective to meet most of the requirements of durable concrete and leads to a significant reduction in CO2 emissions. This research studies the effect different SCMs (natural pozzolan (PN) / limestone fine (FC) at various replacement levels) on the physical and mechano-chemical resistance of blended mortar. The paper primarily deals with the characteristics of these materials, including heat of hydration, strength and effects of aggressive chemical environments (using sulphuric acid and nitric acid). Over 6 mixes were made and compared to the control mix. Tests were conducted at different ages up to 360 days. The experimental results in general showed that Algerian mineral admixtures (PN/FC) were less vulnerable to nitric and sulphuric acid attack and improved the properties of mortars, but at different rates depending on the quantity of binder.