<script type="text/javascript">
//disable default scroll 
map.scrollWheelZoom.disable();
  $("#map").bind('mousewheel DOMMouseScroll', function (event) {
    event.stopPropagation();
    if (event.ctrlKey == true) {
      event.preventDefault();
      map.scrollWheelZoom.enable();
      $('#map').removeClass('map-scroll');
      setTimeout(function(){
        map.scrollWheelZoom.disable();
        }, 1000);
      } else {
        map.scrollWheelZoom.disable();
        $('#map').addClass('map-scroll');
        }
    });

$(window).bind('mousewheel DOMMouseScroll', function (event) {
  $('#map').removeClass('map-scroll');
  })
</script>