After retiring from J. Muller International his colleagues remembered him as an engineer that could take a very complicated problem and reduce it to a few pages of calculations. A prime example of this was his match-casting and segmental bridge section techniques. His match-casting invention consisted of pre-cast segmental sections being cast together and then separated. This made it possible for the sections to fit perfectly together when constructed at the job site, and reduced construction time significantly. Before match-casting, pre-cast concrete bridge segments were connected using cast-in-place mortar joints. Cast-in-place joints meant that the sections were mortared together at the bridge construction site while
cranes or structural supports held up the pre-cast segments. However, if match-cast sections were used, mortared joints were not necessary. Instead, an
epoxy was applied to both surfaces of the sections to be joined. The sections fit perfectly together and no fillers were required to patch voids on the joint surfaces. Since there were no voids on the joint surfaces the entire cross-sectional area of the joint was in contact providing enough area to produce an extremely strong connection. ==Recognition and awards== • The
Franklin Institute awarded Muller the
Frank P. Brown Medal in 1995 for "developing a method of match-casting of pre-cast concrete elements." • During its 125th anniversary in 1999,
Engineering News Record recognized Muller as one of the top 125 people to contribute to engineering and construction. ==Religion==