This act shall be known as the Government Construction Management At-Risk Contracts Act. The provisions of this article may be used to select construction managers at-risk for authorized public construction projects as set forth in this article. Notwithstanding the provisions of §5-22-1 et seq. and §5-22A-1 et seq. of this code, construction management at-risk contracts shall be awarded pursuant to the provisions of this article: Provided, That a construction management at-risk contract shall not be authorized for a construction project of less than $20 million in estimated total cost.