Technology: general issues 46 History of engineering and technology 37 TA Engineering (General). Civil engineering (General) 28 Slags 23 History of engineering & technology 12 Blast furnaces 11 Compressive strength 10 Research & information: general 8 Materials science 7 Mining technology and engineering 7 Sustainable development 6 Fly ash 5 Ground granulated blast furnace slag 5 Hydrated lime 4 Mortar 4 Research and information: general 4 Sodium hydroxide 4 TJ Mechanical engineering and machinery 4 Water absorption 4 compressive strength 4 slag 4 sustainability 4 Alumina 3 Aluminum oxide 3 Carbon dioxide 3 Chemistry 3 Concrete aggregates 3 Electric arcs 3 Electric furnaces 3 Energy utilization 3