Dr. Saal is noted for his fundamental research on the constitution and properties of asphalt. He has made important contributions to the knowledge of the rheology of asphalts and is recognized as one of the first experts on the scientific development of mechanical test procedures for asphalts.
A key member of J. Ph. Pfeiffer’s research team working in the Royal Dutch – Shell Laboratory in Amsterdam, Holland, he became leader of the group upon the death of Dr. Pfeiffer.
From 1927 to 1931, Dr. Saal was a research chemist with Koninklijke – Shell Laboratorium in Amsterdam; from 1931 – 1947, he was in charge of various sections, and since 1942, his work has been mainly on basic properties of asphaltic bitumen. He was head of the bitumen research department from 1947 to 1961, when he retired.