1. Fine recycled concrete powder used as filler and cement replacement in new concrete
Jaroslav TOPIČ, Zdeněk PROŠEK, Jan TREJBAL, Josef FLÁDR,
Tomáš PLACHÝ
Department of Mechanics, Faculty of Civil Engineering, CTU in Prague,

2. OBJECTIVES Ecological re-use of recycled concrete powder
Thermal dehydration of C-S-H gel
Raw material for Portland clinker production
high power demands and CO2 production
Part of geopolymer binder
Microfiller and partial cement replacement
- high speed milling => cement grains exposure

3. METHODS Fresh cement paste with 50 wt. % of
recycled concrete powder, w/c=0.35
Hydration heat measurement
Cement pastes with 0, 33, 67 and 100 wt. % of recycled concrete powder
Flexural strength test
Compressive strength test
Dynamic Young´s modulus
- resonance method

4. RESULTS
Hydration heat measurement
Mechanical properties

5. THANKS FOR YOUR ATTENTION