I want my wordpress loop to only display posts of the standard format

Use get_post_format() inside your loop:

if (have_posts()) :
  while (have_posts()) :
    the_post();
    $format = get_post_format();
    if (false === $format) {
      get_template_part('content', get_post_format());
    }
  endwhile;
  twentyfourteen_paging_nav();
else :
  get_template_part('content', 'none');
endif;