id	keyword
american_scientific_journal-2326	cement
american_scientific_journal-2326	nano
american_scientific_journal-2326	graphene
american_scientific_journal-2326	mortar
american_scientific_journal-2326	strength
american_scientific_journal-2326	sheets
american_scientific_journal-2326	research
american_scientific_journal-2326	figure
american_scientific_journal-2326	materials
american_scientific_journal-2326	days
american_scientific_journal-2326	engineering
american_scientific_journal-2326	properties