Section 27D. Wherever used in sections twenty-six to twenty-seven C, inclusive, the words ''construction'' and ''constructed'' as applied to public buildings and public works shall include additions to and alterations of public works, the installation of resilient flooring in, and the painting of, public buildings and public works; certain work done preliminary to the construction of public works, namely, soil explorations, test borings and demolition of structures incidental to site clearance and right of way clearance; and the demolition of any building or other structure ordered by a public authority for the preservation of public health or public safety.