The Laboratory for Concrete

Activities

• surveys, tests, measurements, technical monitoring, preparation of technical reports, analyses and final assessments,
• monitoring of systems and procedures for assessing and verification of the quality of concretes for Slovenia's motorway construction program (third party control),
• initial and periodical verification of the production capacity of concrete batching-plants, including homogenization tests,
• initial tests of concretes for voluntary certification procedures,
• inspection tests of concretes for the certification of factory production control,
• measurements of the transverse electrical resistance of floorings,
• investigation of the quality of installed concretes.
  

Determination of the properties of concretes in the laboratory and in the field

Fresh concretes:

• consistence (slump, flow, Ve-Be, and other non-standard methods (SCC),
• entrained air content,
• binding and hardening times,
• density,
• water-cement ratio,
• temperature.

Hardened concretes:

• compressive, flexural, tensile and splitting strength,
• density, water absorption,
• elasticity, toughness and deformation states,
• watertightness of concretes and coatings for concretes, gas absorption of hardened concretes in the laboratory or in situ,
• resistance to weathering effects (freezing/thawing, drying/soaking),
• volumetric deformation during drying under loading or without loading,
• the analysis of systems of air pores,
• ultrasound tests in the field and in the laboratory.
  

Investigation of the compressive strength of concrete in buildings:

• by drilling cores,
• by using the rebound test hammer or ultrasonic method,
• by combined methods.
  

Testing of concrete products

• gas and foamed concrete products,
• concrete and reinforced-concrete pipes, inspection chambers and manholes,
• building-blocks, roof tiles, kerbs, paving elements, slabs, fence elements, garden furniture, gutters, box drains, drainage channels, distance pieces,
• fibre-cement roof and facade elements,
• lime-sand building-blocks,
• building-blocks made from autoclave-foamed concrete.
  

Research work

• investigations in the field of the optimization of the composition of high-strength concretes - correlation of the properties of fresh concrete and concrete paste,
• research into composite materials on the basis of magnesium cement,
• investigation of microscopic composition of clay that has been stabilized using cement and fly ash,
• studies of the properties of cementitious materials containing waste materials,
• participation in the introducing of new methods of testing of concretes and concrete products,
• participation in research into the use of acoustic techniques when monitoring the development of cracks and damage to concrete and reinforced-concrete beams.

Most important testing and measuring equipment

• several universal testing-machines for determining the mechanical properties of concrete and concrete products,
• equipment for determining the depth of penetration of water into concrete,
• equipment for determining the surface and internal resistance of concrete to freezing,
• equipment for simulating weather-induced loadings of roof covering elements (precipitation / heat; drying / soaking; freezing / soaking),
• equipment for determining the watertightness of concrete pipes with lengths up to 3 m and diameters up to 1000 mm
• equipment for determining the properties of fresh self-compacting concrete.

Within the scope of the Department for Materials:

• a low-vacuum scanning electron microscope (SEM) and energy dispersive x-ray spectrometer (EDX)
  

Important projects realized since 1998

* MPZ - the Ministry RS of Transport and Communications
** MG - the Ministry RS of the Economy
*** MŠZŠ - the Ministry RS of Education, Science and Sport