Self-compactibility of flowing sand-concrete containing dune sand and marble powder

This paper evaluates the self-compactibility of flowing sand-concretes (FSC) mixtures, incorporated various dune sand and marble powder contents, by testing flowability (determined by slump flow and v-funnel tests), passing ability (determined by L-box test) and segregation (determined by the visual stability index). The compressive strength at 28 days was also determined. Results show that the slump flow of all FSC mixtures lie between 450 and 840 mm, thus satisfying flowability according the recommendations of AFGC, except for the mixture made with 150 kg/m3 of marble powder (with a slump flow of 450 mm). V-funnel flow time, T500 time and L-box ratio of all mixtures were about 1.7-3.8 s, 0.6-2.3 s and 0.5-0.93 respectively. These results indicate that FSC have a v-funnel time shorter than the range proposed by EFNARC recommendations (8-12 s). Despite lower v-funnel times, no visual stability loss has been observed for all studied mixtures (all mixtures have a visual segregation index of 0 and 1)

Editorial for inaugural issue

Welcome to the inauguration issue of our new publication: Journal of Building Materials and Structures (JBMS). JBMS has been installed thanks to the open source solutions developed by Public Knowledge Project. My great thanks also goes out to my co-editors and editorial office team for accepting to guide with me this journal from initial planning to the first steps it is taking now.The main objective of JBMS is to provide a repository of knowledge for building materials and structural engineering sciences. The choice of open access format to JBMS is to ensure free access to knowledge which is linked to the economic development and seems in agreement to the spirit of scientific thought. It is important to note that all contributions, upon approval by our peer review process, are for beginning, indexed in Google Scholar and archived in the Open Archive Initiative (OAI).The peer review procedure will match knowledgeable reviewers with submitted manuscripts to produce high quality articles of interest and scientific merit. The procedure is confidential so that recommendations and revisions are made in the fairest way possible. The final decision on publication will be made by the editor in charge.As new teaching systems, such as License-Master-Doctorate (LMD) system or the national project works carried out by researchers, take root in universities and laboratories, especially across Algeria, the roles that conducting research projects and writing scientific articles play within these institutions are increasing.In light of this development, our new journal looks at the potential of new researches and high quality contribution works within laboratories and universities, as well as the ways in which research development can impact beyond higher journal articles quality.Finally, I thank our contributors and readers for their interest and efforts in completing this inauguration issue and I also look forward to a most interesting future for JBMS

ANN modelling approach for predicting SCC properties - Research considering Algerian experience .Part II. Effects of aggregates types and contents

The objective of this investigation is to illustrate the effect of aggregates types and contents on fresh and hardened properties of self-compacting concrete (SCC) considering Algerian experience. Based on experimental data available in the literature, Artificial neural network (ANN) models are established to illustrate the variation of aggregate types and contents (sand and gravel) in binary and ternary contour plots. Modelling results concerning the effect of sand types and proportions in binary and ternary combinations show the beneficial effect of river sand (RS) and crushed sand (CS) on slump flow. The highest L-Box ratio was obtained for mixtures composed of 50% of both RS and CS for binary and ternary mixtures. The increase in CS content enhance static stability, while the increase in RS gives higher compressive strength at 28 days. Concerning the study of aggregate sizes and contents, it was found that the increase of sand content leads to an increase in flowability and a decrease in static stability. An increase in gravel content leads to a decrease in passing ability, while a significant improvement in viscosity, static stability and mechanical strength with an increase in gravel content were observed

Self-compactibility of flowing sand-concrete containing dune sand and marble powder

This paper evaluates the self-compactibility of flowing sand-concretes (FSC) mixtures, incorporated various dune sand and marble powder contents, by testing flowability (determined by slump flow and v-funnel tests), passing ability (determined by L-box test) and segregation (determined by the visual stability index). The compressive strength at 28 days was also determined. Results show that the slump flow of all FSC mixtures lie between 450 and 840 mm, thus satisfying flowability according the recommendations of AFGC, except for the mixture made with 150 kg/m3 of marble powder (with a slump flow of 450 mm). V-funnel flow time, T500 time and L-box ratio of all mixtures were about 1.7-3.8 s, 0.6-2.3 s and 0.5-0.93 respectively. These results indicate that FSC have a v-funnel time shorter than the range proposed by EFNARC recommendations (8-12 s). Despite lower v-funnel times, no visual stability loss has been observed for all studied mixtures (all mixtures have a visual segregation index of 0 and 1)

Mixture design approach to evaluate fresh properties of SCC made with various sands

The aim of the present paper is to provide a mixture design modelling to evaluate the effect of different sand types on fresh properties of self-compacting concrete (SCC). A statistical approach was used to highlight the effect of river sand (RS), crushed sand (CS) and dune sand (DS) as proportions in binary and ternary systems in SCC composition. The responses of the derived statistical models are sand packing density (SPD), T500 and J-ring. The resulting mathematical models are used to illustrate the variation of different responses in ternary contours plots with respect to the proportions of RS, CS and DS. This offers flexibility to optimize RS, CS and DS blends with tailor-made of a given property that suit a particular recommendations. Results indicate that SPD of RS can be enhanced by a 40% of CS and 30% of DS proportions. Moreover, it is shown that flowability, measured by J-ring, can be improved by the increase of CS and DS in RS-CS and RS-DS binary systems. Results also indicate that passing ability measured with T500 decreased with the increase of CS proportion and increased with the increase of DS proportion in binary and ternary systems

Mix proportioning and performance of a crushed limestone sand-concrete

Satisfying the ever-growing demand of concrete aggregates poses a problem in many parts of the world due to shortage of natural sand. Moreover, to conserve natural resources and protect civil engineering infrastructures, there is a need to find alternative materials. Crushed stone sand has been identified as a potential substitute material for natural sand in making good quality concrete. The main objective of the present investigation is to determine an adequate mix design method and evaluate engineering properties of crushed limestone sand concrete mixtures in both the fresh and hardened sates. More than thirty concrete mixtures were examined. The results indicate that water demand and cement paste content in crushed sand concrete are generally higher than that used in similar conventional concrete. Good mechanical properties were obtained for concrete using crushed limestone sand as fine aggregates with a superplasticizer. However, a higher than normally used dosage of superplasticizer is required in these concrete mixtures and the optimum dosage of the superplasticizer needs to be determined for each cement and sand content

Caractérisation physico-mécanique des ciments allégés à base de matériaux locaux, en vue de leur utilisation dans la cimentation des puits de pétrole dans les zones salifères

108 p. : ill. ; 30 cmL'élaboration de laitiers composés de ciment, d'eau d'additifs chimiques, dépend des conditions thermodynamiques et géologiques du puits. C'est le cas des puits contenant des couches salifères, oû on doit utiliser des ciments allégés pour éviter l'éffrondement des ces couches, mais la présence de sel dans la formation peut engender de sérieux problèmes pendant et aprés cimentatio