to finance construction expenditures) shall apply to the available construction proceeds of bonds issued under this section. For purposes of the preceding sentence, the following spending requirements shall apply in lieu of the requirements in clause (ii) of such section: (A) 40 percent of such available construction proceeds are spent for the governmental purposes of the issue within the 2-year period beginning on the date the bonds are issued. (B) 60 percent of such proceeds are spent for such purposes within the 3-year period beginning on such date. (C) 80 percent of such proceeds are spent for such purposes within the 4-year period beginning on such date. (D) 100 percent of such proceeds are spent for such purposes within the 5-year period beginning on such date. (3) Repayments of principal on financing provided by the issue— (A) may not be used to provide financing, and (B) must be used not later than the close of the first semiannual period beginning after the date of the repayment to redeem bonds which are part of such issue. The requirement of subparagraph (B) shall be treated as met with respect to amounts received within 5 years after the date of issuance of the issue (or, in the case of a refunding bond, the date of issuance of the original bond) if such amounts are used by the close of such 5 years to redeem bonds which are part of such issue. (4) Section 57(a)(5) shall not apply. (f) Separate issue treatment of portions of an issue This section shall not apply to the portion of an issue which (if issued as a separate issue) would be treated as a qualified bond or as a bond that is not a private activity bond (determined without regard to paragraph (1)), if the issuer elects to so treat such portion. (g) Qualified disaster area