# Durability of High Volume Glass Powder Self-Compacting Concrete
## 4 Conclusions  
This study presented an overview of the influence of glass powder particle size and replacement level on the durability indicators for self-compacting concrete. Oxygen permeability, porosity, electrical  
\begin{table}
\begin{tabular}{c c c c c c c} \hline  & **OPC** & **FAF30\%** & **10G30\%** & **20G20\%** & **20G30\%** & **20G40\%** & **40G30\%** \\ \hline Cover (75), Ct (0.1) & 8 & 47.3 & 143.7 & 150+ & 87.8 & 25.6 & 34.9 \\ Cover (75), Ct (0.05) & 5.4 & 28.5 & 91.8 & 136.3 & 54.9 & 15 & 20.6 \\ Cover (50), Ct (0.1) & 3.7 & 16.6 & 57.7 & 86.3 & 33.4 & 9.3 & 12.3 \\ Cover (50), Ct (0.05) & 2.37 & 9.9 & 33.6 & 55 & 18.5 & 5.7 & 7.4 \\ \hline \end{tabular}
\end{table}
Table 6: Comparison of time to corrosion initiation for different binder replacement levels, covers and threshold concentrations.  
Figure 16: Comparison of corrosion initiation time for different concrete mixes.  
resistivity, chloride diffusivity and drying shrinkage of glass modified SCC were compared with GP and fly ash mixes. The main findings from the study can be summarized as follows:  
* The amount and particle size of incorporated waste glass has a significant influence on the mechanical and durability properties of SCC. Glass powder replacement level of 20-30% showed better performance as compared to fly ash and GP mixes. Moreover, the filling effect of small-sized glass particles results in improved particle packing, forming a denser and less permeable microstructure.
* The lower shrinkage strains for glass powder concrete mixes will help reduce the risk of cracking associated with long-term drying. The drying shrinkage values of all waste glass incorporating mixes, irrespective of their fineness and content, were below 0.075% after 56-days drying and met the requirements of the Australian Standard AS 3600.
* The lower oxygen permeability and chloride diffusion coefficient along with high electrical resistivity of glass incorporated SCC mixes confirms a refinement of pore structure due to pozzolanic reaction leading to increase in tortuosity and thereby inhibiting free movement of ions.
* The higher ageing coefficients for the glass powder mixes as compared to GP and fly ash mixes indicate continuous evolution and refinement of the pore structure, which results in better long-term transport performance of the binder system and considerable extension in terms of service-life for concrete exposed to marine environment.  
[PERSON] performed the experimental testing, analysed the results and prepared the initial draft of the paper under the guidance of her supervisors [PERSON] and [PERSON]; [PERSON] and [PERSON] both provided advice and guidance on research direction and assisted with the interpretation of the data in addition to writing of the manuscript. [PERSON] helped with analysis of the data and in the preparation and revision of the manuscript. All authors have read and agreed to the published version of the manuscript.  
This research was partially funded by the Building Research Association of New Zealand (BRANZ).  
The authors would like to acknowledge the contributions of BRANZ, the Glass Packaging Forum and Golden Bay Cement for their support.  
The authors declare no conflict of interest.