Input value from a DateTime Boostrap From

I try to get the value from the Datetime Boostrap but it's seems to doesn't work . someone have an idea ? where i'm doing wrong ? by the way the colum dt_rencontre is a Datetime type in my database

here my view with the form :

<div class="input-group date form_datetime">
                                    <div class="input-group-addon">
                                        <i class="fa fa-calendar"></i>
                                    </div>
                                    <input type="text" class="form-control pull-right" value="13/06/2017 14:30">
                                </div>

here my controller who should get the value :

public function store(Request $request)
    {

        $rencontre = new Rencontre;

        $rencontre->dt_rencontre = $request->input('value');

...

via Mathieu Mourareau