Structuration of natural muds in a rheological point of view.

This paper discusses the filling of estuary problem which can be defined as the accumulation of fine materials that causes the invasion of muds all over the estuary and that has a direct effect on the fauna and flora in the river, fishing, swimming and the beauty of the landscapes. All this consequences have social, environmental and economic impact. In the context of the study of this phenomena, analysis of the structuration mechanisms of sedimentary materials in estuaries is carried out in order to better understand the fillings estuarine areas and specially to consider sustainable solutions of “cleansing” of these areas. The Rance estuary is particularly targeted by the study. The aim is to provide answers on the rheological behavior of natural vessels by distinguishing the most significant scales to detect structural factors influencing the rheological parameters

Concurrent cisplatin, continuous infusion fluorouracil and radiotherapy followed by tailored consolidation treatment in non metastatic anal squamous cell carcinoma

BACKGROUND: To evaluate efficacy and feasibility of chemo-radiotherapy in patients with non-metastatic anal squamous-cell-cancer. METHODS: TNM staged anal squamous-cell cancer patients were treated with pelvic radiotherapy concomitant to continuous infusion fluorouracil plus cisplatin for at least 2 cycles. In T3-T4 or any T - N+ tumours or in "slow-responder" cases, 1-2 chemotherapy courses were subsequently administered. Tumour assessment was performed at baseline and 6-8 weeks after radiotherapy to evaluate response. RESULTS: 29 patients were enrolled: 4 males, 25 females; median age 57 years; baseline T1/T2/T3/T4 2/12/7/8; N involvement 17. Median dose pelvic radiotherapy was 59.4 Gy (range: 54-74). In 5 patients 2 chemotherapy courses, in 12 patients three and in 12 patients four courses were performed. At first evaluation, 27 CR (93.1%; 95% CI: 78% - 98%) and 2 SD were observed. Main grade (G) 3 toxic events were neutropenia (8%), diarrhoea (8%) and dermatitis (62%). Most frequent late events G3-G4 occurred in 14 patients: proctitis (5), dermatitis (4), bladder dysfunctions (2), sexual dysfunctions (9), lower extremity venous thromboses (2), dysuria (1), stenosis (1) and tenesmus (1). Five patients reported G1 leucopoenia. The rate of colostomy was 14%. After a median follow up of 42 months (range: 4-81), 20 patients are still alive without relapse and 3 died due to PD. The estimated 7-year DFS was 83.4% (C.I.: 68.3%-98.5%) and the estimated 7-year OS was 85.7% (C.I.: 70% - 100%). The 1-year and the estimated 7-year colostomy-free survivals were 85.9% (C.I.: 73.1% - 98.7%). CONCLUSIONS: Concurrent cisplatin plus fluorouracil and radiotherapy is associated with favourable local control rates and acute toxicity. Future investigations will be directed towards research into molecular biomarkers related to disease progression and resistance to chemo-radiotherapy and to the evaluation of new cytotoxic agents or targeted drugs, such as anti-epidermal growth factor receptor, concomitant to RT and to determining the role of intensity-modulated radiotherap

Fondations superficielles sur colonnes ballastées : comparaison des tassements mesurés et calculés

Cette communication présente une synthèse de plusieurs exemples de projets sensibles aux tassements qui ont fait l’objet de suivis de tassements du début jusqu’à la fin de la construction. Les tassements mesurés seront comparés aux calculs des méthodes usuelles de dimensionnement de colonnes ballastées (Priebe, PLAXIS, méthode des recommandations des colonnes ballastées)

Structural built-up of cement-based materials used for 3D-printing extrusion techniques

International audienceAdditive manufacturing and digital fabrication bring new horizons to concrete and cement-based material construction. 3D printing inspired construction techniques that have recently been developed at laboratory scale for cement-based materials. This study aims to investigate the role of the structural build-up properties of cement-based materials in such a layer by layer construction technique. As construction progresses, the cement-based materials become harder with time. The mechanical strength of the cement-based materials must be sufficient to sustain the weight of the layers subsequently deposited. It follows that the comparison of the mechanical strength, which evolves with time (i.e. structural build-up), with the loading due to layers subsequently deposited, can be expected to provide the optimal rate of layer by layer construction. A theoretical framework has been developed to propose a method of optimization of the building rate, which is experimentally validated in a layer-wise built column

Densification de sols fins compressibles par colonnes ballastées : étude expérimentale en laboratoire de l’influence du mode de mise en place

Cette étude s’intéresse à la consolidation des sols fins lors de la mise en place de colonnes ballastées. Plus précisément, on cherche à mettre en évidence le rôle du mode de mise en place de l’élément granulaire sur la densification du sol encaissant. L’étude est réalisée expérimentalement en laboratoire. La mise en place d’une colonne ballastée est dans ce cas simulée par la mise en place d’une colonne de sable au sein d’une éprouvette d’argile. Plusieurs colonnes de sables sont réalisées pour différents mode de mise en place (avec et sans refoulement) et pour différents efforts de compactage en cours de construction. L’influence de l’effort de compactage est analysé. Ensuite, on s’intéresse au comportement mécanique du sol renforcé. Pour ce faire, les éprouvettes renforcées (sol contenant une colonne mise en place suivant l’un ou l’autre mode) sont soumise à un même chargement uniforme. L’influence du diamètre de la colonne d’une part et du mode de mise en place d’autre part sur la réduction des tassements est ainsi analysée

Gravity induced flow to characterize rheological properties of printable cement‐based materials

International audienceThis paper presents testing methods based on the deformation and fracture of fresh cementitious materials subjected only to their own weight. These new methods are dedicated to the study of cementitious materials designed for 3D concrete printing in order to verify rheological requirements related to the process. The first testing method consists of measuring the tip deflection of fresh cementitious materials, horizontally extruded, enabling the determination of the apparent elastic modulus of the material. The second test consists of measuring the tensile strength of material filament leaving the nozzle of a vertical downward extruder. The results of both methods are based on the video capture of the deformation of the materials loaded by gravity, and provide results that are in agreement with tests performed with conventional testing machines (tensile and unconfined compression tests). This work demonstrates the potential of video capture of the gravity induced deformation of cementitious materials to describe the behavior of cementitious materials in the fresh state or for the in‐line control of the 3D concrete printing process. © The Author(s) 2020

Structuration of natural muds in a rheological point of view.

This paper discusses the filling of estuary problem which can be defined as the accumulation of fine materials that causes the invasion of muds all over the estuary and that has a direct effect on the fauna and flora in the river, fishing, swimming and the beauty of the landscapes. All this consequences have social, environmental and economic impact. In the context of the study of this phenomena, analysis of the structuration mechanisms of sedimentary materials in estuaries is carried out in order to better understand the fillings estuarine areas and specially to consider sustainable solutions of “cleansing” of these areas. The Rance estuary is particularly targeted by the study. The aim is to provide answers on the rheological behavior of natural vessels by distinguishing the most significant scales to detect structural factors influencing the rheological parameters