1. Sofia Real, José Alexandre Bogas, Maria da Glória Gomes
Durability and thermal performance of structural lightweight aggregate concrete produced with different types of cementitious materials
Sofia Real, José Alexandre Bogas, Maria da Glória Gomes
1. Motivation and Objectives
Characterization of the durability and thermal performance of energy efficient structural lightweight aggregate concrete (SLWAC) produced with different types of lightweight aggregate (LWA) and binder
Definition of recommended guidelines for the production of durable SLWAC in different exposure conditions
2. Research Significance
Few studies have been published concerning the durability and service life design of SLWAC, especially for different types of binder and exposure environments. Also, the main normative documents are relatively recent and are often adaptations of the existing normalization for normal weight concrete (NWC). So far, such a comprehensive study on the durability of innovative and better energy efficient solutions with durable SLWAC has never been done.
Figure 1 – Different types of LWA
3. Methodology
Physical and mechanical characterization of LWA (Figure 1)
Selection of different concrete compositions
Fresh SLWAC properties
Physical and mechanical characterization of SLWAC (Figure 2)
Durability characterization of SLWAC in laboratory and in real environmental exposure conditions (Figures 3-4)
Semi-probabilistic and probabilistic models for concrete service life assessment
4. Results and conclusions
Figure 2 – Thermal characterization
Strength and density classes ranged LC12/13-LC60/66 and D1.6-D2.0
Thermal conductivity of SLWAC can be 50% lower than that of NWC [1]
SLWAC can contribute to the reduction of thermal bridges and energy needs [2]
Laboratory test results indicate that for a reasonable service life period, SLWAC can be as durable as NWC [3]
LWA can participate in the transport mechanisms of concrete, especially in concrete with a high w/b ratio [4]
A new biphasic carbonation model was proposed [5]
The semi-probabilistic service life study based on laboratory tests showed that SLWAC can surpass the 50 year intended service life [6-7]
The monitorization of the specimens exposed to natural environments and the probabilistic service life analysis are still in progress
Figure 3 – Durability characterization
References
[1] Real S., Bogas J.A., Gomes M.G., Ferrer B. Thermal conductivity of structural lightweight aggregate concrete. Mag. Conc. Res. 68 (15) (2015)
[2] Real S., Gomes M.G., Moret Rodrigues A., Bogas J.A. Contribution of structural lightweight aggregate concrete to the reduction of thermal bridging effect in buildings. Const. Build. Mat. 121 (2016)
[3] Real S., Bogas J.A., Pontes J. Chloride migration in structural lightweight aggregate concrete produced with different binders. Const. Build. Mat. 98 (2015) 425–436.
[4] Real S., Bogas J.A. Oxygen permeability of structural lightweight aggregate concrete. Const. Build. Mat. 137 (2017) 21–34.
[5] Bogas J.A., Real S., Ferrer B. Biphasic carbonation behaviour of structural lightweight aggregate concrete produced with different types of binder. Cem. Conc. Comp. 71 (2016)
[6] Ferrer B., Bogas J.A., Real S. Service life of structural lightweight aggregate concrete under carbonation-induced corrosion. Const. Build. Mat. 120 (2016) 161–171.
[7] Real S., Bogas J.A., Ferrer B. Service life of reinforced structural lightweight aggregate concrete under chloride-induced corrosion. Materials and Structures 50(2) (2017) 1-17.
Figure 4 – Different environmental exposure conditions