This appears to be a high margin business (EBITDA/sales >20%)...

This appears to be a high margin business (EBITDA/sales >20%) and also growing strongly (20+% in revenues and EBITDA). Quite a bit of capex in the past year or two with new quarries and concrete plants being built. Something that is both a potential strength and weakness is that they are pushing into specialized custom-made products like crossbeams, precast deck girders and such. Could be a strength because these are niche areas where the likes of Adelaide Brighton or Boral do not/cannot compete. Potential weakness is that it requires specialized sales/marketing teams that need to focus intensely into wharf projects, road structures, bridges, wind energy projects and such. Potential is great if they can develop further into custom-made project structures for civil and structural works. 

Nevertheless it is still too expensive at P/E of 21 and performance in any period can be quite lumpy, depending on project works. I think it is good value under $2.