Representatives from nearly a dozen construction trade unions will answer questions and offer demonstrations at the second annual Construction Apprenticeship Expo on Tuesday.

About 200 high school and intermediate school students are expected at the event in the morning, and the fair will be opened to the public from noon to 3 p.m., said Blayne Hanagami, Hawai'i branch manager and the Workforce Development Division of the state Department of Labor and Industrial Relations.

The fair will be at the Hawai'i Army National Guard Armory near the Hilo airport.