id	keyword
american_scientific_journal-2944	aggregates ratio
american_scientific_journal-2944	strength
american_scientific_journal-2944	concrete
american_scientific_journal-2944	cement
american_scientific_journal-2944	compressive
american_scientific_journal-2944	portland
american_scientific_journal-2944	cement ratio
american_scientific_journal-2944	engineering
american_scientific_journal-2944	days