I'm sure that this is not the best option but at least it works.

Go to admin/structure/types/manage/YOUR_CONTENT_TYPE/display and select the `Title Formatter` for your field, and then use this code:

    $nid = 76;
    $node = \Drupal::service('entity.manager')->getStorage('node')->load($nid);
    foreach ($node->field_aaaa as $i => $delta) {   
      dpm($delta->value);
      dpm($node->field_aaaa->view('full')[$i]['#markup']);
    }

You will see this:

    * id_string1
    * String 1
    * id_string2
    * String 2
    * id_string3
    * String 3

**EDIT:** The correct way using the [@4k4][1] answer is:

    $nid = 76;
    $node = \Drupal::service('entity.manager')->getStorage('node')->load($nid);
    foreach ($node->field_aaaa as $i => $delta) {   
      dpm($delta->value);
      dpm((string) \Drupal::service('renderer')->render($delta->view(array('type' => 'title_formatter'))));
    }


  [1]: https://drupal.stackexchange.com/a/240009/28275