But some projects have been suspended or slowed down due to insufficient funding.
The NDRC said the pace of projects that have now resumed has accelerated since May.
To help cut costs and risks, the Ministry of Finance announced in March that local governments would be permitted to swap 1 trillion yuan ($163 billion) of high-interest local debt for new official municipal or provincial bonds.
Lian Ping, chief economist at the Bank of Communications, said such deleveraging of local debt and the promotion of public-private partnerships would be key for infrastructure investment growth in the second half of the year.
He said fixed-asset investment was mainly dragged down by slow growth in new housing development and in manufacturing investment.
Elsewhere, the NBS figures showed investment in the secondary industry, or the industrial sector of the economy dominated by the manufacture of finished products, declined by 0.4 percentage point year-on-year in the first half. Investment in mining, manufacturing, power and gas all saw slower investment growth.
Infrastructure continued to be a major driver of overall investment, rising 19.1 percent in the first half, up 1 percentage point from the first five months.