English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Ce travail s'inscrit dans le cadre du projet national a Fond Unique Interministeriel, nomme ERGOFORM (ERGOnomic FORMwork-Systeme de coffrage auto-stable diminuant la penibilite de chantier), qui vise a mettre au point un procede de coffrage innovant. Quatre pâtes de ciment ont ete elaborees avec des rapports Eau sur Ciment (E/C) de respectivement 0,30, 0,35, 0,40 et 0,45. L'evolution des proprietes physiques et mecaniques des pâtes de ciment ont ete mesurees : la porosite accessible a l'eau sous vide, les resistances a la compression et en flexion trois points. L'evolution des parametres de rugosite en fonction du temps de cure a ete analysee par microscopie interferometrique et microscopie electronique a balayage environnemental (MEB-E). Les resultats experimentaux montrent que l'augmentation du dosage en ciment diminue la porosite accessible a l'eau et ameliore les proprietes mecaniques a 24h (apres decoffrage nomme T0). L'evolution de la porosite en fonction du temps de cure montre une augmentation se stabilisant apres 4 jours d'immersion dans l'eau pour les pâtes cimentaires de rapports E/C de 0,40 et de 0,45 (Groupe 2). En revanche, cette augmentation se prolonge legerement pour les pâtes de ciment 0,30 et 0,35 (Groupe 1). Par ailleurs, l'evolution des parametres de rugosite est fonction du dosage en ciment. En effet, les analyses microscopiques et par diffraction des rayons X mettent en evidence une diminution de la quantite des pores en surface, mais aussi l'evolution des parametres de rugosite par un changement de sa morphologie et la formation de portlandite meme apres 2 heures de cure normalisee. : The experimental study is part of the national project ERGOnomic FORMwork (Self-Stable Formwork System Reducing Site Difficulty) named ERGOFORM, which aims to develop an innovative formwork process for construction field. Four cement pastes were provided with different water-to-cement ratio (W/C), respectively, 0.30, 0.35, 0.40 and 0.45. The evolution of physical and mechanical properties of cement pastes was measured through water porosity under vacuum, compressive strength and flexural strength. The variation of the roughness parameters was performed by the interferometry microscope. The environmental scanning electron microscopy (E-SEM) was used to analyze the evolution of the surface morphology. The experimental results show that the increase of cement quantity decreases the water porosity and improves the mechanical properties of studied mix designs at 24 hours (after stripping, called T0). The evolution of porosity versus curing time shows that the variation stabilizes after 4 days of immersion in water for the ratio W/C 0.40 and 0.45, named G2 (Group 2). On the other hand, this variation slightly continued for cement pastes 0.30 and 0.35, named G1 (Group 1). Moreover, the evolution of roughness parameters is dependent on cement quantity in mix design. Indeed, the MEB coupling EDX and X-ray diffraction analyzes reveal a decrease in the amount of surface pores, but also the evolution of the roughness parameters by a change in its morphology and the formation of portlandite even after 2 hours of standardized cure.

Effet de l’hydratation et du rapport E/C sur les paramètres de la rugosité de surface de pâtes cimentaires