id	keyword
american_scientific_journal-1130	waste
american_scientific_journal-1130	c&d
american_scientific_journal-1130	building
american_scientific_journal-1130	construction
american_scientific_journal-1130	recycling
american_scientific_journal-1130	tanzania
american_scientific_journal-1130	aggregates
american_scientific_journal-1130	cradle
american_scientific_journal-1130	concrete
american_scientific_journal-1130	production
american_scientific_journal-1130	material