Experiments on drying, selfdesiccation and shrinkage of concrete with different water cement ratio

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F18%3A00327276" target="_blank" >RIV/68407700:21110/18:00327276 - isvavai.cz</a>

Výsledek na webu

—

DOI - Digital Object Identifier

—

Jazyk výsledku

angličtina

Název v původním jazyce

Experiments on drying, selfdesiccation and shrinkage of concrete with different water cement ratio

Popis výsledku v původním jazyce

The paper is focused on experimental investigation of moisture movement in cementitious materials and related phenomena such as pore relative humidity development, self-desiccation, moisture loss, autogenous and drying shrinkage. Experimental layout involved four different concrete mixtures from ordinary concrete to ultra-high performance concrete (UHPC) with water cement ratio varying in the range 0,25 – 0,52. All mixtures were manufactured industrially at concrete mixing plant during 8 hours in order to ensure as much as possible similar initial conditions. Characteristic compressive strength measured on cubes laid in the range 47 – 144 MPa. Different types of specimens were used: standard cylinders (150x300 mm) were designated for investigation of autogenous and drying shrinkage; segments of slab (300x300x100 mm) were chosen for measurement of moisture loss and pore relative humidity development; standard cubes (150 mm) were used for measurement of self-desiccation and compressive strength. Specimens were left in moulds with sealed upper surface for the period of 6 days. Afterwards they were demoulded and prepared for final storage. Surfaces of the specimens which were not intended to dry were sealed with synthetic resin. Environmental conditions in the laboratory were not controlled, however temperature and relative humidity were measured every 5 minutes using a datalogger. Effect of water cement ratio emerge very strongly from the results of shrinkage as well as drying, moisture loss and self-desiccation. Initial behaviour emphasized the complex character of volume changes during hydration and also raised a lot of questions regarding methodology and time of commencement of measurements of volume changes of concrete.

Název v anglickém jazyce

Experiments on drying, selfdesiccation and shrinkage of concrete with different water cement ratio

Popis výsledku anglicky

The paper is focused on experimental investigation of moisture movement in cementitious materials and related phenomena such as pore relative humidity development, self-desiccation, moisture loss, autogenous and drying shrinkage. Experimental layout involved four different concrete mixtures from ordinary concrete to ultra-high performance concrete (UHPC) with water cement ratio varying in the range 0,25 – 0,52. All mixtures were manufactured industrially at concrete mixing plant during 8 hours in order to ensure as much as possible similar initial conditions. Characteristic compressive strength measured on cubes laid in the range 47 – 144 MPa. Different types of specimens were used: standard cylinders (150x300 mm) were designated for investigation of autogenous and drying shrinkage; segments of slab (300x300x100 mm) were chosen for measurement of moisture loss and pore relative humidity development; standard cubes (150 mm) were used for measurement of self-desiccation and compressive strength. Specimens were left in moulds with sealed upper surface for the period of 6 days. Afterwards they were demoulded and prepared for final storage. Surfaces of the specimens which were not intended to dry were sealed with synthetic resin. Environmental conditions in the laboratory were not controlled, however temperature and relative humidity were measured every 5 minutes using a datalogger. Effect of water cement ratio emerge very strongly from the results of shrinkage as well as drying, moisture loss and self-desiccation. Initial behaviour emphasized the complex character of volume changes during hydration and also raised a lot of questions regarding methodology and time of commencement of measurements of volume changes of concrete.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

20101 - Civil engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Fib Congres 2018, Better - Smarter - Stronger (Full papers)

ISBN

978-1-877040-14-6

ISSN

—

e-ISSN

—

Počet stran výsledku

8

Strana od-do

151-158

Název nakladatele

fib - fédération internationale du béton

Místo vydání

Lausanne

Místo konání akce

Melbourne

Datum konání akce

7. 10. 2018

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

—