Universal Portland Cement Co., C. W. Boynton · Universal Portland Cement Co. · leaf 46
s willgreatly accelerate the hardening of the concrete, thus developingmore rapidly in the walk a condition which makes it capableof resisting frost action. Even though heated materials are used,the surface covering should not be neglected, for by failure toprotect the surface, the heat in the walk… … Figure 23. The necessity of providing perfect joints in a walk is distinctly shown inFigures 22 and 23. These figures also show the advisability of projecting thejoints from the old into the new work, or the necessity of providing an open jointbetween walks laid at different times. In both pictures…
![An illustration from XIXe [i.e. Dix-neuvième] siècle (en France); classes - moeurs - usages - costumes - inventions. Ouvrage illustré d'un front. chromotypographique, de 16 planches coloriées aux patrons, de 36 entetes et lettres ornées et de 487 gravures (dont 24 tirées hors texte) d'après les principaux artistes du siècle (1893)](https://img.insideoutlibrary.com/img/200/ia-xixeiedixneuvi00granuoft-674-493.webp)
