The Norwegian Public Roads Administration conducts research and development activities to support improvements in bridge and tunnel design standards. Their 2022 R&D budget is NOK 4.15 million. Current projects include studies of bridge maintenance, post-tensioned reinforcement corrosion, the effects of supplementary cementitious materials, and alkali-silica reactions. Field exposure sites evaluate concrete durability under marine and cold weather conditions. Internal R&D also examines topics like chloride diffusion in concrete over time.

1. Concrete R&D activities involvement
- Norwegian Public Roads Administration
Øyvind Bjøntegaard and Bård Pedersen
Road Directorate, section Structural Engineering

2. Concrete
technology
Leader
Bridge design
Tunnel and
geology
Our main responsibilities
• Regulations for Bridge design
(Handbook N400)
• Regulations for Road tunnels
(Handbook N500)
• Associated guidelines
• Authority for assessing
applications for derogations
(fraviksbehandling)
• R&D, as basis for revisions
• Standardization (nat./int.)
NPRA, section Structural Engineering

3. R&D
● In 2022 our R&D-budget is NOK 4,15 mill (EUR 400.000)
● R&D-involvement, motive:
- To support development, and in green direction
- To implement new knowledge in our regulations
- To follow development and secure own competence
● See reference list in the paper for reports and publications
● All NPRA-reports are open and available on:
https://www.vegvesen.no/fag/publikasjoner/publikasjoner/statens-vegvesens-
rapporter/
NPRA, section Structural Engineering

4. ● R&D-program; Improved Bridge Maintenance (2017-2022)
Closing conference 21. Sept 2022
● Maintenance of post-tensioned reinforcement
• Spin-off from Improved Bridge Maintenance
● Field exposure sites / marine exposure
• The oldest site is nearly 30 years
• The newest is 5 years
● Various activities in NPRA’s own laboratory, for instance:
• Study of the chloride diffusion coefficient aging exponent
● Casting of drilled steel pipe piles
Internal R&D

5. ● NewsCem (2018-2022): New Supplementary Materials in Cement Production
• Norcem is project owner. Totally 12 partners -- Recently concluded!
• Follow-up project is recently granted; Zero Carbon Emission Concrete (2022-2026) - ZeroCarbCon
● MESLA (2021-2025): Management and extension of service life of infrastructures affected by ASR
• NTNU is project owner. Totally 10 partners. (see Jan Lindgård, session B1)
● Concrete C100 and related structural design topics for the E39 project (2018-2022).
• Cooperation with NTNU. Financed by NPRA. (see Terje Kanstad, session A2)
● Field tests at RISE’s field station at Rv40/Borås. Salt/frost exposure.
• Status after 4 years exposure is reported. 8 years status will be recorded this autumn.
● Investigation of 30 years offshore concretes. Marine exposure. Cooperation with DNV
● SUPERCON (2019-2023): Sprayed sustainable permanent robotized concrete tunnel lining.
• SINTEF is project owner. Totally 16 partners. (see Nicholas Trussell, session A7)
● Safe use of local aggregate in concrete – effect of sulphide minerals on durability of concrete
• PhD-study (2020-2024), Nikolas Oberhardt
Joint R&D projects

6. Project; Improved Bridge Maintenance
Test site for different cathodic protection
systems
Crushing of bridge deck end due to ASR
WP 1 Reinforcement corrosion
WP 2 Alkali-silica reactions (see Kathrine M. Stemland, session B1)
WP 3 Bridge management tools
WP 4 Maintenance of steel bridges
Available reports from the project Improved Bridge Maintenance:
https://vegvesen.brage.unit.no/vegvesen-xmlui/handle/11250/2616457

7. Project; Maintenance of post-tensioned reinforcement
Corrosion in post-tensioned cables
About 2300 pre- and post-
tensioned bridges in Norway
- Inspection methods
- Repair methods

8. ● Concrete elements:
– 0,4 x 0,2 m cross section
– 2,7 m long
● Non-instrumented elements
– Drilling of cores, chloride profiles/ingress
● Instrumented elements
– Electro-chemical potential
– Galvanic current
– Temperature
● Start exposure of elements:
– 2017/2018: NPRA elements, produced by DTI
(fly-ash, slag, w/b-ratio)
– 2022: Elements produced within NewsCem,
owned by Norcem (new SCMs)
Marine exposure site Austefjorden (near Bergen)
NPRA finances a 3-year PostDoc on assessment of field data over 30 years
- Malene Thostrup Pedersen -

9. RISE’s exposure site, Borås/Sweden (salt/frost-resistance)
● Study of the effect of high volume fly-
ash and slag concretes
– Frost, chloride, lab/field relation, etc
● Lab. and field up to 4 years:
– R&D cooperation NPRA / RISE
– Report; see link given in paper
● New registration in 2022 (8 years)
Photos: RISE

10. NPRA’s own laboratory
Example:
● Concretes plates (250 x 400 x 100 mm)
stored in sea-water over many years
(from 7 days age)
● Study of the chloride diffusion coefficient
development over time
– The aging coefficient
● Such data is relevant for:
– the exposure resistance class system in
the upcoming Eurocode 2
– and especially for new cements with new
SCMs where there is lack of long term
experience
y = 1,4672x-0,217
R² = 0,9851
y = 1,5825x-0,391
R² = 0,9703
y = 1,9029x-0,629
R² = 1
0,1
1,0
10,0
1,00 10,00
Chloride
diffusion
Coefficient,
10
-12
m
2
/s
Exposure time (Years)

11. ● Small amounts of pyrite (FeS2) and
pyrrhotite (Fe1-xS) may cause expansion and
cracking
For instance, blasted tunnel rock masses are
rarely used as concrete aggregate today in
Norway due to varying rock types and possible
traces of pyrrhotite.
EN 12620 have requirements, BUT:
- Detection of sulfide minerals is difficult.
- Small amounts ↔ Accuracy of methods
● PhD-study (financed by NPRA)
– Detection methods and their accuracy
– Reaction mechanisms in concrete
– Limit values for acceptable content (in
high quality concrete)
Safe use of local aggregate in concrete – effect of sulphide minerals on
durability of concrete

12. ● Under-water casting operation
● Shown to be challenging
– Especially at the tip of the
pile (the start-up casting
procedure)
● Sometimes up to 70 m long piles
● New Norwegian Guideline
recently published
Casting of drilled steel pipe piles

13. ● Standardization work, EN 1504-series
● Own research:
– One category of mortars may have
very different properties
– Requirements for repair mortars
The pictures illustrate a challenge with
piecewise repair in connection with
chloride induced corrosion
– The conditions for corrosion may
change along the edge of the
repaired zones
Mechanical repair / repair mortars