SD Vision - Halyps Cement

many architectural possibilities of the selfcompacting
concrete. This new cultural
space, located in avenue Kennedy in La
Rochelle, is part of a broader plan and will
host private and public events as well as
performances. This hall with a 400 seating
capacity is going to become the heart of
the local social life.
The 1,650 m 2 building consists of an entrance
to the lobby, a service area and a
few other service rooms. There is a double
access to the hall from the lobby on either
side of the service area. The construction
of the village hall of Mireuil in La Rochelle
presented constraints on the materials and
the installation technique. The architect
prescribed white 10m-high curved and
moulded walls: a major challenge that the
construction company overcame in partnership
with Unibéton by choosing white
self-compacting Isytecvoil concrete. This
building site implied 3 specifi c technical requests
for Unibéton: the use of a smooth
and homogenous concrete of a peculiar
white color (the fi rst application of white
self-compacting concrete in the region)
cast with moulded formworks.
In order to satisfy these requirements,
Unibéton developed and tested on site a
specifi c formulation combining strength,
fl uidity and dynamism related to viscosity.
This concrete contains white cement
CEM 2 42,5 Ciments Calcia and GSM
aggregates, it is a good mix of limestone
and superplasticizer and has an A/S (aggregates/sand)
ratio of about 1. The whole
façade of the building is decorated with
portraits of famous celebrities from the
world of entertainment. In addition to a
daring and aesthetic architecture, the Party
and Performance Hall of Mireuil is environmentally
friendly since it fully complies
with the HQE ® standards (HQE ® for
Special Industrial Concrete – High Environmental
Quality, and HPE for Very-high performance
fi bre-reinforced concrete – High
Energy Performance). The project manager
opted for procedures and materials contributing
to an environmentally friendly,
sustainable building.
The Metz hospital
Located less than seven kilometers away
from the city centre, this regional hospital
is built on an 11-hectar parcel of land. This
project, with a budget of 150 million euro,
is different from the traditional model of
hospital subdivided into different wards
“Chantier Bleu”: Metz hospital, France
since a net separation of activities is no
longer compatible with modern medical
practices. With a capacity of 640 beds
and a fl oor area of 87,000 m 2 the new
regional hospital consists of four blocks: a
surgery unit, a cardio-vascular and neurological
pole, a haematology, oncology and
pneumology ward and a medical-technical
facility with a central fl oor deck. This
“Chantier Bleu”, named after the environmental
management quality label
developed by Quille, has undergone
a prescription procedure and many
preliminary studies. The CTG carried out
temperature simulations to control the
temperature rise and the risk of cracking
among the different components of the
radiology room under control. In order to
improve the working conditions on this
building site and to comply with the Quille
label standards, the whole building (except
for the foundations) is erected with selfcompacting
concrete. With a capacity
of 30 m 3 /h, the mobile plant produced
about 50,000 m 3 of self-compacting
concrete with Axim Cimfl uid Adagio 2019
admixture. Morever, GSM provided four
different types of alluvial aggregates while
Tratel provided the two Unibéton units
with CEM II B 32,5 R and CEM I 52,5 N
from the Ciments Calcia plant in Rombas.
The Seine Aval
wastewater treatment plant
The Seine Aval wastewater treatment
plant, managed by the SIAAP (Syndicat interdépartemental
pour l’assainissement de
l’agglomération parisienne), is the world’s
second largest purifying station (after
the WWTP of Chicago) and, in the last few
years, was subject to a major renovation
plan aimed at improving its environmental
performance. The entire project involved
between 700,000 m 3 and 750,000 m 3 of
concrete supplied by a Unibéton
plant installed at the building
site (set up in one week) and its
local partner. The sewage treatment
building consisted of an
effl uent basin and an administrative
area. Only the latter is
visible while the rest, built inside
a 10m-deep excavation, is
covered with vegetation. The
basin, that contains 50,000 m 3
of water, is made of dense concrete
to guarantee its watertightness
and contains pre-walls. The
whole structure is built with BPSCC C 35/
45 XA2 containing CEM5 32,5 PMES as
recommended by SIAAP in order to offer
increased resistance to effl uents.
Currently the plant treats 30% of the nitrifi
ed water. Since the Directive on Urban
Wastewater Treatment requires this rate
to reach 70%, a 40% increase in the
treatment of nitrifi ed water will be attained
through the implementation of 18
watertight cells sealed between them and
connected to a pipe system. Since the cells
are anchored at 14m depth, the impact
on the neighboring water table had to be
taken into account and a groundwater
lowering was performed with 16 pumping
wells to be able to start working. The
thickness of the walls varies from 50 to
70 cm according to the areas. Finding the
adequate thickness is important to resist
the pressure of water (adjacent cells can
be either full or empty) and of the surrounding
ground because this structure is
underground too. However, it will not be
fi lled in and covered with vegetation but
rather surmounted by an aesthetic covering
in BSI - Special Industrial Concrete
(BFUP - VeryPerfetto Dariohigh performance
fi bre-reinforced concrete). In order
to meet the considerable needs of this
building site, Unibéton produced 11 formulas
for concrete on site, 2 of which
self-compacting and more fl uid, thus ideal
for structures with many metal parts. Four
formulas are CEM5-based and produce
high strength concretes suitable to aggressive
environments. Beds and walls are
in CEM5-based concrete. The parts not
directly in contact with the effl uents are
made of BPSCC C35/ 45 XC3 with CEM1
52,5 N. All these concretes contain sand
and aggregates from GSM. The CEM5based
compounds have been repeatedly
laboratory tested with SIKA and BASE.
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