As part of efforts to cope with a shortage of construction sand and aggregates, the South Korean government is planning to make recycling of aggregate mandatory, the Ministry of Construction and Transportation and the Ministry of Environment said today.  The shortage of aggregate worsened following a recent government crackdown on the construction sector’s use of beach sand, which was implemented to protect the environment.  Against such a backdrop, the ministries will soon commission private and state-run research institutes to study ways to recycle used aggregate, officials said.  The government will also devise ways to encourage collection of aggregate in a more environmentally friendly way by the end of May.